Nano-linked metallocene catalyst compositions and their polymer products

ABSTRACT

The present invention provides polymerization catalyst compositions employing novel dinuclear metallocene compounds. Methods for making these new dinuclear metallocene compounds and for using such compounds in catalyst compositions for the polymerization and copolymerization of olefins are also provided.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of olefinpolymerization catalysis, catalyst compositions, methods for thepolymerization and copolymerization of olefins, and polyolefins. Morespecifically, this invention relates to nano-linked dinuclearmetallocene compounds and catalyst compositions employing suchcompounds.

A dinuclear metallocene compound can be produced via an olefinmetathesis reaction, for example, as shown in Chem. Eur. J., 2003, 9,pp. 3618-3622. Olefin metathesis is a catalytic reaction betweencompounds that contain olefinic (e.g., alkene) moieties. Catalysts thatare often employed in an olefin metathesis reaction include metals suchas ruthenium, tungsten, molybdenum, or nickel.

SUMMARY OF THE INVENTION

The present invention generally relates to new catalyst compositions,methods for preparing catalyst compositions, methods for using thecatalyst compositions to polymerize olefins, the polymer resins producedusing such catalyst compositions, and articles produced using thesepolymer resins. In particular, the present invention relates tonano-linked dinuclear metallocene compounds and catalyst compositionsemploying such compounds. Catalyst compositions containing nano-linkeddinuclear metallocene compounds of the present invention can be used toproduce, for example, ethylene-based homopolymers and copolymers.

The present invention discloses novel dinuclear metallocene compoundshaving two metallocene moieties linked by an alkenyl group. According toone aspect of the present invention, these dinuclear compounds have theformula:

wherein:

X¹ and X² independently are a halide or a substituted or unsubstitutedaliphatic, aromatic, or cyclic group, or a combination thereof;

X³ is a substituted or unsubstituted cyclopentadienyl, indenyl, orfluorenyl group, any substituents on X³ independently are a hydrogenatom or a substituted or unsubstituted alkyl or alkenyl group;

X⁴ is a substituted cyclopentadienyl, indenyl, or fluorenyl group, anysubstituents on X⁴ other than an alkenyl linking group independently area hydrogen atom or a substituted or unsubstituted alkyl or alkenylgroup;

M is Zr, Hf, or Ti;

R^(X), R^(Y), and R^(Z) independently are a hydrogen atom, or asubstituted or unsubstituted aliphatic, aromatic, or cyclic group, or acombination thereof; and

n is an integer in a range from 0 to 12, inclusive;

with the proviso that the integer n is not equal to 0 when both X¹ andX² are chlorine atoms, both X³ and X⁴ are cyclopentadienyl groups,R^(X), R^(Y), and R^(Z) are each hydrogen atoms, and M is Ti.

Catalyst compositions containing these nano-linked dinuclear metallocenecompounds are also provided by the present invention. In one aspect, acatalyst composition is disclosed which comprises a contact product ofat least one dinuclear metallocene compound and at least one compoundselected from at least one aluminoxane compound, at least one organozinccompound, at least one organoboron or organoborate compound, at leastone ionizing ionic compound, or any combination thereof. In this aspect,the dinuclear compound is as defined above in formula (I).

In another aspect, a catalyst composition comprising a contact productof at least one dinuclear metallocene compound and at least oneactivator-support is provided. This catalyst composition can furthercomprise at least one organoaluminum compound, as well as otherco-catalysts. In these and other aspects, the at least one dinuclearmetallocene compound is selected from:

wherein:

X¹ and X² independently are a halide or a substituted or unsubstitutedaliphatic, aromatic, or cyclic group, or a combination thereof;

X³ is a substituted or unsubstituted cyclopentadienyl, indenyl, orfluorenyl group, any substituents on X³ independently are a hydrogenatom or a substituted or unsubstituted alkyl or alkenyl group;

X⁴ is a substituted cyclopentadienyl, indenyl, or fluorenyl group, anysubstituents on X⁴ other than an alkenyl linking group independently area hydrogen atom or a substituted or unsubstituted alkyl or alkenylgroup;

M is Zr, Hf, or Ti;

R^(X), R^(Y), and R^(Z) independently are a hydrogen atom, or asubstituted or unsubstituted aliphatic, aromatic, or cyclic group, or acombination thereof; and

n is an integer in a range from 0 to 12, inclusive;

with the proviso that the integer n is not equal to 0 when both X¹ andX² are chlorine atoms, both X³ and X⁴ are cyclopentadienyl groups,R^(X), R^(Y), and R^(Z) are each hydrogen atoms, and M is Ti.

The present invention also contemplates a process for polymerizingolefins in the presence of a catalyst composition, the processcomprising contacting the catalyst composition with at least one olefinmonomer and optionally at least one olefin comonomer underpolymerization conditions to produce a polymer or copolymer. Thecatalyst composition can comprise a contact product of at least onedinuclear metallocene compound and at least one activator-support. Otherco-catalysts, including organoaluminum compounds, can be employed inthis process.

Polymers produced from the polymerization of olefins, resulting ineither homopolymers or copolymers, can be used to produce variousarticles of manufacture.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 presents an NMR plot of MET 1.

FIG. 2 presents an NMR plot of Example 1 after 40 days.

FIG. 3 presents a mass spectrum plot of Example 2.

FIG. 4 presents a dynamic melt viscosity versus frequency plot, measuredat 190° C., for the polymers of Examples 3-8.

DEFINITIONS

To define more clearly the terms used herein, the following definitionsare provided. To the extent that any definition or usage provided by anydocument incorporated herein by reference conflicts with the definitionor usage provided herein, the definition or usage provided hereincontrols.

The term “polymer” is used herein to mean homopolymers comprisingethylene and copolymers of ethylene and a comonomer. “Polymer” is alsoused herein to mean homopolymers and copolymers of any olefin monomerdisclosed herein (e.g., propylene).

The term “co-catalyst” is used generally herein to refer toorganoaluminum compounds that can constitute one component of a catalystcomposition. Additionally, “co-catalyst” refers to other components of acatalyst composition including, but not limited to, aluminoxanes,organozinc compounds, organoboron or organoborate compounds, ionizingionic compounds, as disclosed herein. The term “co-catalyst” is usedregardless of the actual function of the compound or any chemicalmechanism by which the compound may operate. In one aspect of thisinvention, the term “co-catalyst” is used to distinguish that componentof the catalyst composition from the dinuclear metallocene compound.

The term “fluoroorgano boron compound” is used herein with its ordinarymeaning to refer to neutral compounds of the form BY₃. The term“fluoroorgano borate compound” also has its usual meaning to refer tothe monoanionic salts of a fluoroorgano boron compound of the form[cation]⁺[BY₄]⁻, where Y represents a fluorinated organic group.Materials of these types are generally and collectively referred to as“organoboron or organoborate compounds.”

The term “contact product” is used herein to describe compositionswherein the components are contacted together in any order, in anymanner, and for any length of time. For example, the components can becontacted by blending or mixing. Further, contacting of any componentcan occur in the presence or absence of any other component of thecompositions described herein. Combining additional materials orcomponents can be done by any suitable method. Further, the term“contact product” includes mixtures, blends, solutions, slurries,reaction products, and the like, or combinations thereof. Although“contact product” can include reaction products, it is not required forthe respective components to react with one another.

The term “precontacted” mixture is used herein to describe a firstmixture of catalyst components that are contacted for a first period oftime prior to the first mixture being used to form a “postcontacted” orsecond mixture of catalyst components that are contacted for a secondperiod of time. Typically, the precontacted mixture describes a mixtureof metallocene compound (or compounds), olefin monomer, andorganoaluminum compound (or compounds), before this mixture is contactedwith an activator-support and optional additional organoaluminumcompound. Thus, precontacted describes components that are used tocontact each other, but prior to contacting the components in thesecond, postcontacted mixture. Accordingly, this invention mayoccasionally distinguish between a component used to prepare theprecontacted mixture and that component after the mixture has beenprepared. For example, according to this description, it is possible forthe precontacted organoaluminum compound, once it is contacted with themetallocene and the olefin monomer, to have reacted to form at least onedifferent chemical compound, formulation, or structure from the distinctorganoaluminum compound used to prepare the precontacted mixture. Inthis case, the precontacted organoaluminum compound or component isdescribed as comprising an organoaluminum compound that was used toprepare the precontacted mixture.

Similarly, the term “postcontacted” mixture is used herein to describe asecond mixture of catalyst components that are contacted for a secondperiod of time, and one constituent of which is the “precontacted” orfirst mixture of catalyst components that were contacted for a firstperiod of time. Typically, the term “postcontacted” mixture is usedherein to describe the mixture of metallocene compound, olefin monomer,organoaluminum compound, and activator-support (e.g., chemically-treatedsolid oxide), formed from contacting the precontacted mixture of aportion of these components with any additional components added to makeup the postcontacted mixture. Generally, the additional component addedto make up the postcontacted mixture is a chemically-treated solidoxide, and, optionally, can include an organoaluminum compound which isthe same as or different from the organoaluminum compound used toprepare the precontacted mixture, as described herein. Accordingly, thisinvention may also occasionally distinguish between a component used toprepare the postcontacted mixture and that component after the mixturehas been prepared.

The term “dinuclear metallocene,” as used herein, describes a compoundcomprising two metallocene moieties linked by a connecting group. Theconnecting group can be an alkenyl group resulting from the metathesisreaction or the saturated version resulting from hydrogenation orderivatization. Thus, the dinuclear metallocenes of this inventioncontain four η³ to η⁵-cyclopentadienyl-type moieties, wherein the η³ toη⁵-cycloalkadienyl moieties include cyclopentadienyl ligands, indenylligands, fluorenyl ligands, and the like, including partially saturatedor substituted derivatives or analogs of any of these. Possiblesubstituents on these ligands include hydrogen, therefore thedescription “substituted derivatives thereof” in this inventioncomprises partially saturated ligands such as tetrahydroindenyl,tetrahydrofluorenyl, octahydrofluorenyl, partially saturated indenyl,partially saturated fluorenyl, substituted partially saturated indenyl,substituted partially saturated fluorenyl, and the like. In somecontexts, the dinuclear metallocene is referred to simply as the“catalyst,” in much the same way the term “co-catalyst” is used hereinto refer to, for example, an organoaluminum compound. Unless otherwisespecified, the following abbreviations are used: Cp forcyclopentadienyl; Ind for indenyl; and Flu for fluorenyl.

The terms “catalyst composition,” “catalyst mixture,” “catalyst system,”and the like, do not depend upon the actual product resulting from thecontact or reaction of the components of the mixtures, the nature of theactive catalytic site, or the fate of the co-catalyst, the dinuclearmetallocene compound, any olefin monomer used to prepare a precontactedmixture, or the activator-support, after combining these components.Therefore, the terms “catalyst composition,” “catalyst mixture,”“catalyst system,” and the like, can include both heterogeneouscompositions and homogenous compositions.

The term “hydrocarbyl” is used herein to specify a hydrocarbon radicalgroup that includes, but is not limited to, aryl, alkyl, cycloalkyl,alkenyl, cycloalkenyl, cycloalkadienyl, alkynyl, aralkyl, aralkenyl,aralkynyl, and the like, and includes all substituted, unsubstituted,branched, linear, heteroatom substituted derivatives thereof.

The terms “chemically-treated solid oxide,” “solid oxideactivator-support,” “treated solid oxide compound,” and the like, areused herein to indicate a solid, inorganic oxide of relatively highporosity, which exhibits Lewis acidic or Brønsted acidic behavior, andwhich has been treated with an electron-withdrawing component, typicallyan anion, and which is calcined. The electron-withdrawing component istypically an electron-withdrawing anion source compound. Thus, thechemically-treated solid oxide compound comprises a calcined contactproduct of at least one solid oxide compound with at least oneelectron-withdrawing anion source compound. Typically, thechemically-treated solid oxide comprises at least one ionizing, acidicsolid oxide compound. The terms “support” and “activator-support” arenot used to imply these components are inert, and such components shouldnot be construed as an inert component of the catalyst composition. Theactivator-support of the present invention can be a chemically-treatedsolid oxide.

Although any methods, devices, and materials similar or equivalent tothose described herein can be used in the practice or testing of theinvention, the typical methods, devices and materials are hereindescribed.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention. The publications discussed throughout the text are providedsolely for their disclosure prior to the filing date of the presentapplication. Nothing herein is to be construed as an admission that theinventors are not entitled to antedate such disclosure by virtue ofprior invention.

For any particular compound disclosed herein, any general structurepresented also encompasses all conformational isomers, regioisomers, andstereoisomers that may arise from a particular set of substituents. Thegeneral structure also encompasses all enantiomers, diastereomers, andother optical isomers whether in enantiomeric or racemic forms, as wellas mixtures of stereoisomers, as the context requires. For example,isomerized and hydrogenated forms of the general structure illustratedin formula (I) are also contemplated.

Applicants disclose several types of ranges in the present invention.These include, but are not limited to, a range of number of atoms, arange of integers, a range of weight ratios, a range of molar ratios,and so forth. When Applicants disclose or claim a range of any type,Applicants' intent is to disclose or claim individually each possiblenumber that such a range could reasonably encompass, including endpoints of the range as well as any sub-ranges and combinations ofsub-ranges encompassed therein. For example, when the Applicantsdisclose or claim a chemical moiety having a certain number of carbonatoms, Applicants' intent is to disclose or claim individually everypossible number that such a range could encompass, consistent with thedisclosure herein. For example, the disclosure that a moiety is a C₁ toC₁₀ linear or branched alkyl group, or in alternative language havingfrom 1 to 10 carbon atoms, as used herein, refers to a moeity that canbe selected independently from an alkyl group having 1, 2, 3, 4, 5, 6,7, 8, 9, or 10 carbon atoms, as well as any range between these twonumbers (for example, a C₁ to C₆ alkyl group), and also including anycombination of ranges between these two numbers (for example, a C₂ to C₄and C₆ to C₈ alkyl group).

Similarly, another representative example follows for the weight ratioof organoaluminum to activator-support in a catalyst compositionprovided in one aspect of this invention. By a disclosure that theweight ratio of organoaluminum compound to activator-support is in arange from about 10:1 to about 1:1000, applicants intend to recite thatthe weight ratio can be selected from about 10:1, about 9:1, about 8:1,about 7:1, about 6:1, about 5:1, about 4:1, about 3:1, about 2:1, about1:1, about 1:5, about 1:10, about 1:25, about 1:50, about 1:75, about1:100, about 1:150, about 1:200, about 1:250, about 1:300, about 1:350,about 1:400, about 1:450, about 1:500, about 1:550, about 1:600, about1:650, about 1:700, about 1:750, about 1:800, about 1:850, about 1:900,about 1:950, or about 1:1000. Additionally, the weight ratio can bewithin any range from about 10:1 to about 1:1000 (for example, theweight ratio is in a range from about 3:1 to about 1:100), and this alsoincludes any combination of ranges between about 10:1 to about 1:1000.Likewise, all other ranges disclosed herein should be interpreted in amanner similar to these two examples.

Applicants reserve the right to proviso out or exclude any individualmembers of any such group, including any sub-ranges or combinations ofsub-ranges within the group, that can be claimed according to a range orin any similar manner, if for any reason Applicants choose to claim lessthan the full measure of the disclosure, for example, to account for areference that Applicants may be unaware of at the time of the filing ofthe application. Further, Applicants reserve the right to proviso out orexclude any individual substituents, analogs, compounds, ligands,structures, or groups thereof, or any members of a claimed group, if forany reason Applicants choose to claim less than the full measure of thedisclosure, for example, to account for a reference that Applicants maybe unaware of at the time of the filing of the application.

While compositions and methods are described in terms of “comprising”various components or steps, the compositions and methods can also“consist essentially of” or “consist of” the various components orsteps.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed generally to new catalystcompositions, methods for preparing catalyst compositions, methods forusing the catalyst compositions to polymerize olefins, the polymerresins produced using such catalyst compositions, and articles producedusing these polymer resins. In particular, the present invention relatesto nano-linked dinuclear metallocene compounds and catalyst compositionsemploying such compounds.

Nano-linked metallocenes of the present invention are dinuclearmolecules in which metallocene moieties are connected by an alkenyllinking group, or nano-link. Nano-linked metallocenes can be designedwith specific angstrom distances between the two metal centers, wherethe distance is determined principally by the connecting linkage orlinking group. The length, stereochemistry, and flexibility or rigidityof the linking group can be used to design catalysts which are eithercapable of, or incapable of, intra-molecular metal-to-metalinteractions. For instance, under the restraint of the nano-link (e.g.,an alkenyl linking group), nano-linked dinuclear metallocenes can offerunique co-catalyst interactions.

Dinuclear Metallocene Compounds

The present invention discloses novel compounds having two metallocenemoieties linked by an alkenyl group, and methods of making these newcompounds. These compounds are commonly referred to as dinuclearcompounds, or binuclear compounds, because they contain two metalcenters. Accordingly, in one aspect of this invention, the dinuclearcompounds have the formula:

wherein:

X¹ and X² independently are a halide or a substituted or unsubstitutedaliphatic, aromatic, or cyclic group, or a combination thereof;

X³ is a substituted or unsubstituted cyclopentadienyl, indenyl, orfluorenyl group, any substituents on X³ independently are a hydrogenatom or a substituted or unsubstituted alkyl or alkenyl group;

X⁴ is a substituted cyclopentadienyl, indenyl, or fluorenyl group, anysubstituents on X⁴ other than an alkenyl linking group independently area hydrogen atom or a substituted or unsubstituted alkyl or alkenylgroup;

M is Zr, Hf, or Ti;

R^(X), R^(Y), and R^(Z) independently are a hydrogen atom, or asubstituted or unsubstituted aliphatic, aromatic, or cyclic group, or acombination thereof; and

n is an integer in a range from 0 to 12, inclusive;

with the proviso that the integer n is not equal to 0 when both X¹ andX² are chlorine atoms, both X³ and X⁴ are cyclopentadienyl groups,R^(X), R^(Y), and R^(Z) are each hydrogen atoms, and M is Ti.

Formula (I) above is not designed to show stereochemistry or isomericpositioning of the different moieties (e.g., this formula is notintended to display cis or trans isomers, or R or S diastereoisomers),although such compounds are contemplated and encompassed by thisformula.

In formula (I), halides include fluorine, chlorine, bromine, and iodineatoms. As used herein, an aliphatic group includes linear or branchedalkyl and alkenyl groups. Generally, the aliphatic group contains from 1to 20 carbon atoms. Unless otherwise specified, alkyl and alkenyl groupsdescribed herein are intended to include all structural isomers, linearor branched, of a given moiety; for example, all enantiomers and alldiastereomers are included within this definition. As an example, unlessotherwise specified, the term propyl is meant to include n-propyl andiso-propyl, while the term butyl is meant to include n-butyl, iso-butyl,t-butyl, sec-butyl, and so forth. For instance, non-limiting examples ofoctyl isomers include 2-ethyl hexyl and neooctyl. Suitable examples ofalkyl groups which can be employed in the present invention include, butare not limited to, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,octyl, nonyl, or decyl, and the like. Examples of alkenyl groups withinthe scope of the present invention include, but are not limited to,ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl,nonenyl, decenyl, and the like.

Aromatic groups and combinations with aliphatic groups include aryl andarylalkyl groups, and these include, but are not limited to, phenyl,alkyl-substituted phenyl, naphthyl, alkyl-substituted naphthyl,phenyl-substituted alkyl, naphthyl-substituted alkyl, and the like.Generally, such groups and combinations of groups contain less than 20carbon atoms. Hence, non-limiting examples of such moieties that can beused in the present invention include phenyl, tolyl, benzyl,dimethylphenyl, trimethylphenyl, phenylethyl, phenylpropyl, phenylbutyl,propyl-2-phenylethyl, and the like. Cyclic groups include cycloalkyl andcycloalkenyl moieties and such moieties can include, but are not limitedto, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, and the like.One example of a combination including a cyclic group is acyclohexylphenyl group. Unless otherwise specified, any substitutedaromatic or cyclic moiety used herein is meant to include allregioisomers; for example, the term tolyl is meant to include anypossible substituent position, that is, ortho, meta, or para.

In formula (I), an alkenyl linking group is an alkenyl group that linksor connects the two metallocene moieties. As illustrated in the aboveformula, the alkenyl linking group is attached to the metallocenemoieties at a cyclopentadienyl, indenyl, or fluorenyl group. X⁴ can haveone or more substituents in addition to the alkenyl linking group.

In one aspect of the present invention, X¹ and X² independently are asubstituted or unsubstituted aliphatic group having from 1 to 20 carbonatoms. In another aspect, X¹ and X² independently are methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, ortrimethylsilylmethyl. In yet another aspect, X¹ and X² independently areethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl,nonenyl, or decenyl. X¹ and X² independently are a substituted orunsubstituted aromatic group, for example, having up to 20 carbon atoms,in another aspect of the present invention.

In a different aspect, X¹ and X² are both chlorine atoms. X¹ and X²independently can be selected from phenyl, naphthyl, tolyl, benzyl,dimethylphenyl, trimethylphenyl, phenylethyl, phenylpropyl, phenylbutyl,propyl-2-phenylethyl, cyclopentyl, cyclopentenyl, cyclohexyl,cyclohexenyl, or cyclohexylphenyl in other aspects of this invention.Yet, in another aspect, X¹ and X² independently are methyl, phenyl,benzyl, or a halide. Further, X¹ and X² independently can be methyl,phenyl, benzyl, or a chlorine atom in another aspect of the presentinvention.

In formula (I), X³ is a substituted or unsubstituted cyclopentadienyl,indenyl, or fluorenyl group, while X⁴ is a substituted cyclopentadienyl,indenyl, or fluorenyl group. In one aspect of the present invention,both X³ and X⁴ are substituted cyclopentadienyl groups. In anotheraspect, X³ is a substituted or unsubstituted cyclopentadienyl group,while X⁴ is a substituted cyclopentadienyl or indenyl group. Yet, inanother aspect, X⁴ is a substituted indenyl group.

X³ can be an unsubstituted cyclopentadienyl, indenyl, or fluorenylgroup. Alternatively, X³ can have one or more substituents. Anysubstituents on X³ independently are a hydrogen atom or a substituted orunsubstituted alkyl or alkenyl group. Hydrogen is included, thereforethe notion of a substituted indenyl and substituted fluorenyl includespartially saturated indenyls and fluorenyls including, but not limitedto, tetrahydroindenyls, tetrahydrofluorenyls, and octahydrofluorenyls.Exemplary alkyls that can be substituents on X³ include methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl, and thelike. In one aspect, each substituent on X³ independently is a hydrogenatom, or a methyl, ethyl, propyl, n-butyl, t-butyl, or hexyl group. Inanother aspect, substituents on X³ are selected independently from ahydrogen atom, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl,octenyl, nonenyl, or decenyl.

X⁴ in formula (I) is a substituted cyclopentadienyl, indenyl, orfluorenyl group, and is substituted with an alkenyl linking group. Inone aspect of this invention, X⁴ contains no further substitutions. X⁴can be further substituted with a hydrogen atom or a substituted orunsubstituted alkyl or alkenyl group in a different aspect of thisinvention. For example, suitable alkyls that can be substituents on X⁴include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,nonyl, or decyl, and the like. In another aspect, excluding the alkenyllinking group, any substituent on X⁴ independently is selected from ahydrogen atom, or an ethyl, propyl, n-butyl, t-butyl or hexyl group. Inyet another aspect, substituents on X⁴ are selected independently from ahydrogen atom, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl,octenyl, nonenyl, or decenyl, exclusive of the aforementioned alkenyllinking group.

In formula (I), substituted aliphatic, aromatic, or cyclic groups, andcombinations thereof, are disclosed, as well as substituted alkyl oralkenyl groups. Such groups described herein are intended to includesubstituted analogs with substitutions at any position on these groupsthat conform to the normal rules of chemical valence. Thus, groupssubstituted with one or more than one substituent are contemplated.

Such substituents, when present, are independently selected from anoxygen group, a sulfur group, a nitrogen group, a phosphorus group, anarsenic group, a carbon group, a silicon group, a germanium group, a tingroup, a lead group, a boron group, an aluminum group, an inorganicgroup, an organometallic group, or a substituted derivative thereof, anyof which having from 1 to about 20 carbon atoms; a halide; or hydrogen;as long as these groups do not terminate the activity of the catalystcomposition. Examples of each of these substituent groups include, butare not limited to, the following groups.

Examples of halide substituents, in each occurrence, include fluoride,chloride, bromide, and iodide.

In each occurrence, oxygen groups are oxygen-containing groups, examplesof which include, but are not limited to, alkoxy or aryloxy groups(—OR^(A)), —OSiR^(A) ₃, —OPR^(A) ₂, —OAlR^(A) ₂, and the like, includingsubstituted derivatives thereof, wherein R^(A) in each occurrence can bealkyl, cycloalkyl, aryl, aralkyl, substituted alkyl, substituted aryl,or substituted aralkyl having from 1 to 20 carbon atoms. Examples ofalkoxy or aryloxy groups (—OR^(A)) groups include, but are not limitedto, methoxy, ethoxy, propoxy, butoxy, phenoxy, substituted phenoxy, andthe like.

In each occurrence, sulfur groups are sulfur-containing groups, examplesof which include, but are not limited to, —SR^(A) and the like,including substituted derivatives thereof, wherein R^(A) in eachoccurrence can be alkyl, cycloalkyl, aryl, aralkyl, substituted alkyl,substituted aryl, or substituted aralkyl having from 1 to 20 carbonatoms.

In each occurrence, nitrogen groups are nitrogen-containing groups,which include, but are not limited to, —NR^(A) ₂ and the like, includingsubstituted derivatives thereof, wherein R^(A) in each occurrence can bealkyl, cycloalkyl, aryl, aralkyl, substituted alkyl, substituted aryl,or substituted aralkyl having from 1 to 20 carbon atoms.

In each occurrence, phosphorus groups are phosphorus-containing groups,which include, but are not limited to, —PR^(A) ₂, —P(OR^(A))₂, and thelike, including substituted derivatives thereof, wherein R^(A) in eachoccurrence can be alkyl, cycloalkyl, aryl, aralkyl, substituted alkyl,substituted aryl, or substituted aralkyl having from 1 to 20 carbonatoms.

In each occurrence, arsenic groups are arsenic-containing groups, whichinclude, but are not limited to, —AsR^(A) ₂, —As(OR^(A))₂, and the like,including substituted derivatives thereof, wherein R^(A) in eachoccurrence can be alkyl, cycloalkyl, aryl, aralkyl, substituted alkyl,substituted aryl, or substituted aralkyl having from 1 to 20 carbonatoms.

In each occurrence, carbon groups are carbon-containing groups, whichinclude, but are not limited to, alkyl halide groups that comprisehalide-substituted alkyl groups with 1 to 20 carbon atoms, aralkylgroups with 1 to 20 carbon atoms, —C(NR^(A))H, —C(NR^(A))R^(A),—C(NR^(A))OR^(A), and the like, including substituted derivativesthereof, wherein R^(A) in each occurrence can be alkyl, cycloalkyl,aryl, aralkyl, substituted alkyl, substituted aryl, or substitutedaralkyl having from 1 to 20 carbon atoms.

In each occurrence, silicon groups are silicon-containing groups, whichinclude, but are not limited to, silyl groups such as alkylsilyl groups,arylsilyl groups, arylalkylsilyl groups, siloxy groups, and the like,which in each occurrence have from 1 to 20 carbon atoms. For example,silicon group substituents include trimethylsilyl and phenyloctylsilylgroups.

In each occurrence, germanium groups are germanium-containing groups,which include, but are not limited to, germyl groups such as alkylgermylgroups, arylgermyl groups, arylalkylgermyl groups, germyloxy groups, andthe like, which in each occurrence have from 1 to 20 carbon atoms.

In each occurrence, tin groups are tin-containing groups, which include,but are not limited to, stannyl groups such as alkylstannyl groups,arylstannyl groups, arylalkylstannyl groups, stannoxy (or “stannyloxy”)groups, and the like, which in each occurrence have from 1 to 20 carbonatoms. Thus, tin groups include, but are not limited to, stannoxygroups.

In each occurrence, lead groups are lead-containing groups, whichinclude, but are not limited to, alkyllead groups, aryllead groups,arylalkyllead groups, and the like, which in each occurrence, have from1 to 20 carbon atoms.

In each occurrence, boron groups are boron-containing groups, whichinclude, but are not limited to, —BR^(A) ₂, —BX₂, —BR^(A)X, and thelike, wherein X is a monoanionic group such as hydride, alkoxide, alkylthiolate, and the like, and wherein R^(A) in each occurrence can bealkyl, cycloalkyl, aryl, aralkyl, substituted alkyl, substituted aryl,or substituted aralkyl having from 1 to 20 carbon atoms.

In each occurrence, aluminum groups are aluminum-containing groups,which include, but are not limited to, —AlR^(A), —AlX₂, —AlR^(A)X,wherein X is a monoanionic group such as hydride, alkoxide, alkylthiolate, and the like, and wherein R^(A) in each occurrence can bealkyl, cycloalkyl, aryl, aralkyl, substituted alkyl, substituted aryl,or substituted aralkyl having from 1 to 20 carbon atoms.

Examples of inorganic groups that may be used as substituents, in eachoccurrence include, but are not limited to, —OAlX₂, —OSiX₃, —OPX₂, —SX,—AsX₂, —PX₂, and the like, wherein X is a monoanionic group such ashydride, amide, alkoxide, alkyl thiolate, and the like, and wherein anyalkyl, cycloalkyl, aryl, aralkyl, substituted alkyl, substituted aryl,or substituted aralkyl group or substituent on these ligands has from 1to 20 carbon atoms.

Examples of organometallic groups that may be used as substituents, ineach occurrence, include, but are not limited to, organoboron groups,organoaluminum groups, organogallium groups, organosilicon groups,organogermanium groups, organotin groups, organolead groups,organo-transition metal groups, and the like, having from 1 to 20 carbonatoms.

Formula (I), depicted above, illustrates that the dinuclear compounds ofthe present invention are homonuclear, because each metallocene moietylinked by the alkenyl linking group is the same and contains the samemetal center. M is selected from Zr, Hf, or Ti in one aspect of thepresent invention. In another aspect, M is Zr or Hf.

R^(X), R^(Y), and R^(Z) in the alkenyl linking group independently areselected from a hydrogen atom, or a substituted or unsubstitutedaliphatic, aromatic, or cyclic group, or a combination thereof. In oneaspect of the present invention, R^(X), R^(Y), and R^(Z) independentlyare a substituted or unsubstituted aliphatic group having from 1 to 20carbon atoms. For example, R^(X), R^(Y), and R^(Z) can be selectedindependently from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,octyl, nonyl, decyl, or trimethylsilylmethyl. In another aspect, R^(X),R^(Y), and R^(Z) are hydrogen atoms. R^(X), R^(Y), and R^(Z)independently are a substituted or unsubstituted aromatic group, forexample, having up to 20 carbon atoms, in yet another aspect of thepresent invention.

R^(X), R^(Y), and R^(Z) independently are a methyl, ethyl, propyl,butyl, pentyl, hexyl, phenyl, naphthyl, tolyl, benzyl, cyclopentyl,cyclohexyl, or cyclohexylphenyl group, or a hydrogen atom, in otheraspects of this invention. Further, R^(X), R^(Y), and R^(Z)independently can be methyl, phenyl, benzyl, or a hydrogen atom inanother aspect of the present invention.

The integer n in formula (I) determines the length of the alkenyllinking group and ranges from 0 to 12, inclusive. In one aspect of thisinvention, n is equal to 0, 1, 2, 3, 4, 5, 6, 7, or 8. In a differentaspect of the present invention, n is 1, 2, 3, 4, 5, or 6. The integer ncan be 1, 2, 3, or 4 in other aspects of this invention.

According to yet another aspect of the present invention, both X¹ and X²are methyl groups, phenyl groups, or benzyl groups. In this aspect, X³is a substituted or unsubstituted cyclopentadienyl or indenyl group, andX⁴ is a substituted cyclopentadienyl or indenyl group. In these andother aspects, M is Zr or Hf; R^(X), R^(Y), and R^(Z) are hydrogenatoms; and n is 0, 1, 2, 3, or 4. Further, X³ can be substituted withone or more substituents, such as methyl, ethyl, propyl, or butylgroups.

In accordance with another aspect of the present invention, both X¹ andX² in formula (I) are chlorine atoms. In this aspect, n is in range from1 to 10, inclusive, and M is Zr, Hf, or Ti. Additionally, X³ can be asubstituted or unsubstituted cyclopentadienyl or indenyl group, and X⁴can be a substituted cyclopentadienyl or indenyl group, in this aspectof the present invention.

An example of a dinuclear compound in accordance with the presentinvention is the following compound, which is abbreviated “DMET 1”throughout this disclosure:

Other illustrative and non-limiting examples of dinuclear metallocenecompounds of the present invention include:

Methods of making a dinuclear compound of the present invention are alsoprovided. One such method for synthesizing a dinuclear metallocenecompound is illustrated in the general reaction scheme provided below:

A metallocene catalyst having an alkenyl substituent is linked to itselfvia the olefin metathesis reaction in the presence of a suitablecatalyst. Generally, the alkenyl substituent can be of any length, andcan be, for example, a substituent on a cyclopentadienyl-type group(e.g., cyclopentadienyl, indenyl, fluorenyl). In the reaction product,the metallocene moieties are connected by an alkenyl linking group.Ethylene gas is also produced in this reaction.

Various metal-based catalysts can be employed in an olefin metathesisreaction. The metals often used include ruthenium, tungsten, molybdenum,and nickel. In the examples that follow, a Grubbs 1st GenerationMetathesis Catalyst based on ruthenium was employed, but this inventionis not limited to any particular metathesis catalyst.

Metathesis reactions can be conducted in the presence of a solvent suchas, for example, aliphatic, aromatic, or saturated ester solvents.Suitable solvents useful in the production of dinuclear metallocenecompounds include, but are not limited to, benzene, toluene, heptane,isobutane, methylene chloride, and the like. Solvent selection candepend upon many factors, for instance, the desired reaction temperatureand solubility of either the metallocene reactant or the dinuclearmetallocene in the particular solvent.

Suitable olefin metathesis reaction temperatures to produce dinuclearmetallocene compounds of the present invention are generally in a rangefrom about −50° C. to about 150° C. For example, the reactiontemperature can be in the range from about 0° C. to about 100° C. Thereaction temperature selected is often a compromise between manyvariables, such as the solvent employed, reaction pressure, reactiontime, quantity and type of catalyst, product yield and selectivity, andisomer ratio, if desired. Further, the metathesis reaction equilibriumcan be driven towards the dinuclear metallocene product if ethylene gasis removed or vented from the reaction system.

Generally, there is no limitation on the selection of the metallocenecompound that can be used to form the dinuclear compounds of the presentinvention, other than the presence of an alkenyl substituent on acyclopentadienyl, indenyl, or fluorenyl group. Some examples ofmetallocene compounds that can be used to produce dinuclear compounds ofthe present invention via the olefin metathesis reaction scheme aboveinclude, but are not limited to:

Other suitable unbridged metallocene compounds include, but are notlimited, to the following:

Additional unbridged metallocene compounds can be used to producedinuclear compounds of the present invention. Therefore, the scope ofthe present invention is not limited to the starting metallocene speciesprovided above.

Catalyst Composition

The present invention also relates to catalyst compositions employingdinuclear metallocene compounds. According to one aspect of the presentinvention, a catalyst composition is provided which comprises a contactproduct of at least one dinuclear metallocene compound and at least oneactivator-support. This catalyst composition can further comprise atleast one organoaluminum compound. These catalyst compositions can beutilized to produce polyolefins, both homopolymers and copolymers, for avariety of end-use applications. The at least one dinuclear metallocenecompound in these catalyst compositions has the formula:

wherein:

X¹ and X² independently are a halide or a substituted or unsubstitutedaliphatic, aromatic, or cyclic group, or a combination thereof;

X³ is a substituted or unsubstituted cyclopentadienyl, indenyl, orfluorenyl group, any substituents on X³ independently are a hydrogenatom or a substituted or unsubstituted alkyl or alkenyl group;

X⁴ is a substituted cyclopentadienyl, indenyl, or fluorenyl group, anysubstituents on X⁴ other than an alkenyl linking group independently area hydrogen atom or a substituted or unsubstituted alkyl or alkenylgroup;

M is Zr, Hf, or Ti;

R^(X), R^(Y), and R^(Z) independently are a hydrogen atom, or asubstituted or unsubstituted aliphatic, aromatic, or cyclic group, or acombination thereof; and

n is an integer in a range from 0 to 12, inclusive;

with the proviso that the integer n is not equal to 0 when both X¹ andX² are chlorine atoms, both X³ and X⁴ are cyclopentadienyl groups,R^(X), R^(Y), and R^(Z) are each hydrogen atoms, and M is Ti.

In accordance with this and other aspects of the present invention, itis contemplated that the catalyst compositions disclosed herein cancontain more than one dinuclear metallocene compound and/or more thanone activator-support. Additionally, more than one organoaluminumcompound is also contemplated.

In another aspect of the present invention, a catalyst composition isprovided which comprises a contact product of at least one dinuclearmetallocene compound, at least one activator-support, and at least oneorganoaluminum compound, wherein this catalyst composition issubstantially free of aluminoxanes, organozinc compounds, organoboron ororganoborate compounds, and ionizing ionic compounds. In this aspect,the catalyst composition has catalyst activity, to be discussed below,in the absence of these additional co-catalysts.

However, in other aspects of this invention, these co-catalysts can beemployed. For example, a catalyst composition comprising at least onedinuclear metallocene compound and at least one activator-support canfurther comprise at least one optional co-catalyst. Suitableco-catalysts in this aspect include, but are not limited to, aluminoxanecompounds, organozinc compounds, organoboron or organoborate compounds,ionizing ionic compounds, and the like, or any combination thereof. Morethan one co-catalyst can be present in the catalyst composition.

In a different aspect, a catalyst composition is provided which does notrequire an activator-support. Such a catalyst composition comprises thecontact product of at least one dinuclear metallocene compound and atleast one compound selected from at least one aluminoxane compound, atleast one organozinc compound, at least one organoboron or organoboratecompound, at least one ionizing ionic compound, or combinations thereof.In this aspect, the at least one dinuclear metallocene compound isselected from:

wherein:

X¹ and X² independently are a halide or a substituted or unsubstitutedaliphatic, aromatic, or cyclic group, or a combination thereof;

X³ is a substituted or unsubstituted cyclopentadienyl, indenyl, orfluorenyl group, any substituents on X³ independently are a hydrogenatom or a substituted or unsubstituted alkyl or alkenyl group;

X⁴ is a substituted cyclopentadienyl, indenyl, or fluorenyl group, anysubstituents on X⁴ other than an alkenyl linking group independently area hydrogen atom or a substituted or unsubstituted alkyl or alkenylgroup;

M is Zr, Hf, or Ti;

R^(X), R^(Y), and R^(Z) independently are a hydrogen atom, or asubstituted or unsubstituted aliphatic, aromatic, or cyclic group, or acombination thereof; and

n is an integer in a range from 0 to 12, inclusive;

with the proviso that the integer n is not equal to 0 when both X¹ andX² are chlorine atoms, both X³ and X⁴ are cyclopentadienyl groups,R^(X), R^(Y), and R^(Z) are each hydrogen atoms, and M is Ti.

Activator-Support

The present invention encompasses various catalyst compositions whichcan include an activator-support. In one aspect, the activator-supportcomprises a chemically-treated solid oxide. Alternatively, theactivator-support can comprise a clay mineral, a pillared clay, anexfoliated clay, an exfoliated clay gelled into another oxide matrix, alayered silicate mineral, a non-layered silicate mineral, a layeredaluminosilicate mineral, a non-layered aluminosilicate mineral, or anycombination thereof.

The chemically-treated solid oxide exhibits enhanced acidity as comparedto the corresponding untreated solid oxide compound. Thechemically-treated solid oxide also functions as a catalyst activator ascompared to the corresponding untreated solid oxide. While thechemically-treated solid oxide activates the metallocene in the absenceof co-catalysts, it is not necessary to eliminate co-catalysts from thecatalyst composition. The activation function of the activator-supportis evident in the enhanced activity of catalyst composition as a whole,as compared to a catalyst composition containing the correspondinguntreated solid oxide. However, it is believed that thechemically-treated solid oxide can function as an activator, even in theabsence of an organoaluminum compound, aluminoxanes, organoboroncompounds, ionizing ionic compounds, and the like.

The chemically-treated solid oxide can comprise at least one solid oxidetreated with at least one electron-withdrawing anion. While notintending to be bound by the following statement, it is believed thattreatment of the solid oxide with an electron-withdrawing componentaugments or enhances the acidity of the oxide. Thus, either theactivator-support exhibits Lewis or Brønsted acidity that is typicallygreater than the Lewis or Brønsted acid strength of the untreated solidoxide, or the activator-support has a greater number of acid sites thanthe untreated solid oxide, or both. One method to quantify the acidityof the chemically-treated and untreated solid oxide materials is bycomparing the polymerization activities of the treated and untreatedoxides under acid catalyzed reactions.

The chemically-treated solid oxide of this invention is formed generallyfrom an inorganic solid oxide that exhibits Lewis acidic or Brønstedacidic behavior and has a relatively high porosity. The solid oxide ischemically-treated with an electron-withdrawing component, typically anelectron-withdrawing anion, to form an activator-support.

According to one aspect of the present invention, the solid oxide usedto prepare the chemically-treated solid oxide has a pore volume greaterthan about 0.1 cc/g. According to another aspect of the presentinvention, the solid oxide has a pore volume greater than about 0.5cc/g. According to yet another aspect of the present invention, thesolid oxide has a pore volume greater than about 1.0 cc/g.

In another aspect, the solid oxide has a surface area of from about 100to about 1000 m²/g. In yet another aspect, the solid oxide has a surfacearea of from about 200 to about 800 m²/g. In still another aspect of thepresent invention, the solid oxide has a surface area of from about 250to about 600 m²/g.

The chemically-treated solid oxide can comprise a solid inorganic oxidecomprising oxygen and at least one element selected from Group 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 of the periodic table, orcomprising oxygen and at least one element selected from the lanthanideor actinide elements. (See: Hawley's Condensed Chemical Dictionary, 11thEd., John Wiley & Sons; 1995; Cotton, F. A.; Wilkinson, G.; Murillo; C.A.; and Bochmann; M. Advanced Inorganic Chemistry, 6^(th) Ed.,Wiley-Interscience, 1999.) For example, the inorganic oxide can compriseoxygen and at least one element selected from Al, B, Be, Bi, Cd, Co, Cr,Cu, Fe, Ga, La, Mn, Mo, Ni, Sb, Si, Sn, Sr, Th, Ti, V, W, P, Y, Zn orZr.

Suitable examples of solid oxide materials or compounds that can be usedto form the chemically-treated solid oxide include, but are not limitedto, Al₂O₃, B₂O₃, BeO, Bi₂O₃, CdO, Co₃O₄, Cr₂O₃, CuO, Fe₂O₃, Ga₂O₃,La₂O₃, Mn₂O₃, MoO₃, NiO, P₂O₅, Sb₂O₅, SiO₂, SnO₂, SrO, ThO₂, TiO₂, V₂O₅,WO₃, Y₂O₃, ZnO, ZrO₂, and the like, including mixed oxides thereof, andcombinations thereof. For example, the solid oxide can be silica,alumina, silica-alumina, aluminum phosphate, heteropolytungstates,titania, zirconia, magnesia, boria, zinc oxide, mixed oxides thereof, orany combination thereof.

The solid oxide of this invention encompasses oxide materials such asalumina, “mixed oxide” compounds thereof such as silica-alumina, andcombinations and mixtures thereof. The mixed oxide compounds such assilica-alumina can be single or multiple chemical phases with more thanone metal combined with oxygen to form a solid oxide compound. Examplesof mixed oxides that can be used in the activator-support of the presentinvention include, but are not limited to, silica-alumina,silica-titania, silica-zirconia, zeolites, various clay minerals,alumina-titania, alumina-zirconia, zinc-aluminate, and the like.

The electron-withdrawing component used to treat the solid oxide can beany component that increases the Lewis or Brønsted acidity of the solidoxide upon treatment (as compared to the solid oxide that is not treatedwith at least one electron-withdrawing anion). According to one aspectof the present invention, the electron-withdrawing component is anelectron-withdrawing anion derived from a salt, an acid, or othercompound, such as a volatile organic compound, that serves as a sourceor precursor for that anion. Examples of electron-withdrawing anionsinclude, but are not limited to, sulfate, bisulfate, fluoride, chloride,bromide, iodide, fluorosulfate, fluoroborate, phosphate,fluorophosphate, trifluoroacetate, triflate, fluorozirconate,fluorotitanate, trifluoroacetate, triflate, and the like, includingmixtures and combinations thereof. In addition, other ionic or non-ioniccompounds that serve as sources for these electron-withdrawing anionsalso can be employed in the present invention.

Thus, for example, the chemically-treated solid oxide used in thecatalyst compositions of the present can be fluorided alumina, chloridedalumina, bromided alumina, sulfated alumina, fluorided silica-alumina,chlorided silica-alumina, bromided silica-alumina, sulfatedsilica-alumina, fluorided silica-zirconia, chlorided silica-zirconia,bromided silica-zirconia, sulfated silica-zirconia, and the like, orcombinations thereof.

When the electron-withdrawing component comprises a salt of anelectron-withdrawing anion, the counterion or cation of that salt can beselected from any cation that allows the salt to revert or decomposeback to the acid during calcining. Factors that dictate the suitabilityof the particular salt to serve as a source for the electron-withdrawinganion include, but are not limited to, the solubility of the salt in thedesired solvent, the lack of adverse reactivity of the cation,ion-pairing effects between the cation and anion, hygroscopic propertiesimparted to the salt by the cation, and the like, and thermal stabilityof the anion. Examples of suitable cations in the salt of theelectron-withdrawing anion include, but are not limited to, ammonium,trialkyl ammonium, tetraalkyl ammonium, tetraalkyl phosphonium, H⁺,[H(OEt₂)₂]⁺, and the like.

Further, combinations of one or more different electron-withdrawinganions, in varying proportions, can be used to tailor the specificacidity of the activator-support to the desired level. Combinations ofelectron-withdrawing components can be contacted with the oxide materialsimultaneously or individually, and in any order that affords thedesired chemically-treated solid oxide acidity. For example, one aspectof this invention is employing two or more electron-withdrawing anionsource compounds in two or more separate contacting steps.

Thus, one example of such a process by which an chemically-treated solidoxide is prepared is as follows: a selected solid oxide compound, orcombination of oxide compounds, is contacted with a firstelectron-withdrawing anion source compound to form a first mixture; thisfirst mixture is calcined and then contacted with a secondelectron-withdrawing anion source compound to form a second mixture; thesecond mixture is then calcined to form a treated solid oxide compound.In such a process, the first and second electron-withdrawing anionsource compounds are either the same or different compounds.

According to another aspect of the present invention, thechemically-treated solid oxide comprises a solid inorganic oxidematerial, a mixed oxide material, or a combination of inorganic oxidematerials, that is chemically-treated with an electron-withdrawingcomponent, and optionally treated with a metal source, including metalsalts, metal ions, or other metal-containing compounds. Non-limitingexamples of the metal or metal ion include zinc, nickel, vanadium,titanium, silver, copper, gallium, tin, tungsten, molybdenum, and thelike, or combinations thereof. Examples of chemically-treated solidoxides that contain a metal or metal ion include, but are not limitedto, zinc-impregnated chlorided alumina, titanium-impregnated fluoridedalumina, zinc-impregnated fluorided alumina, zinc-impregnated chloridedsilica-alumina, zinc-impregnated fluorided silica-alumina,zinc-impregnated sulfated alumina, chlorided zinc aluminate, fluoridedzinc aluminate, sulfated zinc aluminate, and the like, or anycombination thereof.

Any method of impregnating the solid oxide material with a metal can beused. The method by which the oxide is contacted with a metal source,typically a salt or metal-containing compound, can include, but is notlimited to, gelling, co-gelling, impregnation of one compound ontoanother, and the like. If desired, the metal-containing compound isadded to or impregnated into the solid oxide in solution form, andsubsequently converted into the supported metal upon calcining.Accordingly, the solid inorganic oxide can further comprise a metalselected from zinc, titanium, nickel, vanadium, silver, copper, gallium,tin, tungsten, molybdenum, and the like, or combinations of thesemetals. For example, zinc is often used to impregnate the solid oxidebecause it can provide improved catalyst activity at a low cost.

The solid oxide can be treated with metal salts or metal-containingcompounds before, after, or at the same time that the solid oxide istreated with the electron-withdrawing anion. Following any contactingmethod, the contacted mixture of oxide compound, electron-withdrawinganion, and the metal ion is typically calcined. Alternatively, a solidoxide material, an electron-withdrawing anion source, and the metal saltor metal-containing compound are contacted and calcined simultaneously.

Various processes are used to form the chemically-treated solid oxideuseful in the present invention. The chemically-treated solid oxide cancomprise the contact product of at least one solid oxide compound and atleast one electron-withdrawing anion source. It is not required that thesolid oxide compound be calcined prior to contacting theelectron-withdrawing anion source. The contact product typically iscalcined either during or after the solid oxide compound is contactedwith the electron-withdrawing anion source. The solid oxide compound canbe calcined or uncalcined. Various processes to prepare solid oxideactivator-supports that can be employed in this invention have beenreported. For example, such methods are described in U.S. Pat. Nos.6,107,230, 6,165,929, 6,294,494, 6,300,271, 6,316,553, 6,355,594,6,376,415, 6,388,017, 6,391,816, 6,395,666, 6,524,987, 6,548,441,6,548,442, 6,576,583, 6,613,712, 6,632,894, 6,667,274, and 6,750,302,the disclosures of which are incorporated herein by reference in theirentirety.

According to one aspect of the present invention, the solid oxidematerial is chemically-treated by contacting it with at least oneelectron-withdrawing component, typically an electron-withdrawing anionsource. Further, the solid oxide material optionally is chemicallytreated with a metal ion, and then calcined to form a metal-containingor metal-impregnated chemically-treated solid oxide. According toanother aspect of the present invention, the solid oxide material andelectron-withdrawing anion source are contacted and calcinedsimultaneously.

The method by which the oxide is contacted with the electron-withdrawingcomponent, typically a salt or an acid of an electron-withdrawing anion,can include, but is not limited to, gelling, co-gelling, impregnation ofone compound onto another, and the like. Thus, following any contactingmethod, the contacted mixture of the solid oxide, electron-withdrawinganion, and optional metal ion, is calcined.

The solid oxide activator-support (i.e., chemically-treated solid oxide)thus can be produced by a process comprising:

1) contacting a solid oxide compound with at least oneelectron-withdrawing anion source compound to form a first mixture; and

2) calcining the first mixture to form the solid oxideactivator-support.

According to another aspect of the present invention, the solid oxideactivator-support (chemically-treated solid oxide) is produced by aprocess comprising:

1) contacting at least one solid oxide compound with a firstelectron-withdrawing anion source compound to form a first mixture;

2) calcining the first mixture to produce a calcined first mixture;

3) contacting the calcined first mixture with a secondelectron-withdrawing anion source compound to form a second mixture; and

4) calcining the second mixture to form the solid oxideactivator-support.

According to yet another aspect of the present invention, thechemically-treated solid oxide is produced or formed by contacting thesolid oxide with the electron-withdrawing anion source compound, wherethe solid oxide compound is calcined before, during, or after contactingthe electron-withdrawing anion source, and where there is a substantialabsence of aluminoxanes, organoboron or organoborate compounds, andionizing ionic compounds.

Calcining of the treated solid oxide generally is conducted in anambient atmosphere, typically in a dry ambient atmosphere, at atemperature from about 200° C. to about 900° C., and for a time of about1 minute to about 100 hours. Calcining can be conducted at a temperatureof from about 300° C. to about 800° C., or alternatively, at atemperature of from about 400° C. to about 700° C. Calcining can beconducted for about 1 hour to about 50 hours, or for about 3 hours toabout 20 hours. Thus, for example, calcining can be carried out forabout 1 to about 10 hours at a temperature of from about 350° C. toabout 550° C. Any suitable ambient atmosphere can be employed duringcalcining. Generally, calcining is conducted in an oxidizing atmosphere,such as air. Alternatively, an inert atmosphere, such as nitrogen orargon, or a reducing atmosphere, such as hydrogen or carbon monoxide,can be used.

According to one aspect of the present invention, the solid oxidematerial is treated with a source of halide ion, sulfate ion, or acombination of anions, optionally treated with a metal ion, and thencalcined to provide the chemically-treated solid oxide in the form of aparticulate solid. For example, the solid oxide material is treated witha source of sulfate (termed a “sulfating agent”), a source of chlorideion (termed a “chloriding agent”), a source of fluoride ion (termed a“fluoriding agent”), or a combination thereof, and calcined to providethe solid oxide activator. Useful acidic activator-supports include, butare not limited to, bromided alumina, chlorided alumina, fluoridedalumina, sulfated alumina, bromided silica-alumina, chloridedsilica-alumina, fluorided silica-alumina, sulfated silica-alumina,bromided silica-zirconia, chlorided silica-zirconia, fluoridedsilica-zirconia, sulfated silica-zirconia; a pillared clay, such as apillared montmorillonite, optionally treated with fluoride, chloride, orsulfate; phosphated alumina or other aluminophosphates optionallytreated with sulfate, fluoride, or chloride; or any combination of theabove. Further, any of these activator-supports optionally can betreated with a metal ion.

The chemically-treated solid oxide can comprise a fluorided solid oxidein the form of a particulate solid. The fluorided solid oxide can beformed by contacting a solid oxide with a fluoriding agent. The fluorideion can be added to the oxide by forming a slurry of the oxide in asuitable solvent such as alcohol or water including, but not limited to,the one to three carbon alcohols because of their volatility and lowsurface tension. Examples of suitable fluoriding agents include, but arenot limited to, hydrofluoric acid (HF), ammonium fluoride (NH₄F),ammonium bifluoride (NH₄HF₂), ammonium tetrafluoroborate (NH₄BF₄),ammonium silicofluoride (hexafluorosilicate) ((NH₄)₂SiF₆), ammoniumhexafluorophosphate (NH₄PF₆), analogs thereof, and combinations thereof.For example, ammonium bifluoride NH₄HF₂ can be used as the fluoridingagent, due to its ease of use and availability.

If desired, the solid oxide is treated with a fluoriding agent duringthe calcining step. Any fluoriding agent capable of thoroughlycontacting the solid oxide during the calcining step can be used. Forexample, in addition to those fluoriding agents described previously,volatile organic fluoriding agents can be used. Examples of volatileorganic fluoriding agents useful in this aspect of the inventioninclude, but are not limited to, freons, perfluorohexane,perfluorobenzene, fluoromethane, trifluoroethanol, an the like, andcombinations thereof. Gaseous hydrogen fluoride or fluorine itself alsocan be used with the solid oxide if fluorided while calcining. Oneconvenient method of contacting the solid oxide with the fluoridingagent is to vaporize a fluoriding agent into a gas stream used tofluidize the solid oxide during calcination.

Similarly, in another aspect of this invention, the chemically-treatedsolid oxide comprises a chlorided solid oxide in the form of aparticulate solid. The chlorided solid oxide is formed by contacting asolid oxide with a chloriding agent. The chloride ion can be added tothe oxide by forming a slurry of the oxide in a suitable solvent. Thesolid oxide can be treated with a chloriding agent during the calciningstep. Any chloriding agent capable of serving as a source of chlorideand thoroughly contacting the oxide during the calcining step can beused. For example, volatile organic chloriding agents can be used.Examples of suitable volatile organic chloriding agents include, but arenot limited to, certain freons, perchlorobenzene, chloromethane,dichloromethane, chloroform, carbon tetrachloride, trichloroethanol, andthe like, or any combination thereof. Gaseous hydrogen chloride orchlorine itself also can be used with the solid oxide during calcining.One convenient method of contacting the oxide with the chloriding agentis to vaporize a chloriding agent into a gas stream used to fluidize thesolid oxide while calcination.

The amount of fluoride or chloride ion present before calcining thesolid oxide generally is from about 2 to about 50% by weight, whereweight percent is based on the weight of the solid oxide, for example,silica-alumina, before calcining. According to another aspect of thisinvention, the amount of fluoride or chloride ion present beforecalcining the solid oxide is from about 3 to about 25% by weight, andaccording to another aspect of this invention, from about 4 to about 20%by weight. Once impregnated with halide, the halided oxide can be driedby any suitable method including, but not limited to, suction filtrationfollowed by evaporation, drying under vacuum, spray drying, and thelike, although it is also possible to initiate the calcining stepimmediately without drying the impregnated solid oxide.

The silica-alumina used to prepare the treated silica-alumina typicallyhas a pore volume greater than about 0.5 cc/g. According to one aspectof the present invention, the pore volume is greater than about 0.8cc/g, and according to another aspect of the present invention, greaterthan about 1.0 cc/g. Further, the silica-alumina generally has a surfacearea greater than about 100 m²/g. According to another aspect of thisinvention, the surface area is greater than about 250 m²/g. Yet, inanother aspect, the surface area is greater than about 350 m²/g.

The silica-alumina utilized in the present invention typically has analumina content from about 5 to about 95% by weight. According to oneaspect of this invention, the alumina content of the silica-alumina isfrom about 5 to about 50%, or from about 8% to about 30%, alumina byweight. According to yet another aspect of this invention, the solidoxide component comprises alumina without silica, and according toanother aspect of this invention, the solid oxide component comprisessilica without alumina.

The sulfated solid oxide comprises sulfate and a solid oxide component,such as alumina or silica-alumina, in the form of a particulate solid.Optionally, the sulfated oxide is treated further with a metal ion suchthat the calcined sulfated oxide comprises a metal. According to oneaspect of the present invention, the sulfated solid oxide comprisessulfate and alumina. In some instances, the sulfated alumina is formedby a process wherein the alumina is treated with a sulfate source, forexample, sulfuric acid or a sulfate salt such as ammonium sulfate. Thisprocess is generally performed by forming a slurry of the alumina in asuitable solvent, such as alcohol or water, in which the desiredconcentration of the sulfating agent has been added. Suitable organicsolvents include, but are not limited to, the one to three carbonalcohols because of their volatility and low surface tension.

According to one aspect of this invention, the amount of sulfate ionpresent before calcining is from about 0.5 parts by weight to about 100parts by weight sulfate ion to about 100 parts by weight solid oxide.According to another aspect of this invention, the amount of sulfate ionpresent before calcining is from about 1 part by weight to about 50parts by weight sulfate ion to about 100 parts by weight solid oxide,and according to still another aspect of this invention, from about 5parts by weight to about 30 parts by weight sulfate ion to about 100parts by weight solid oxide. These weight ratios are based on the weightof the solid oxide before calcining. Once impregnated with sulfate, thesulfated oxide can be dried by any suitable method including, but notlimited to, suction filtration followed by evaporation, drying undervacuum, spray drying, and the like, although it is also possible toinitiate the calcining step immediately.

According to another aspect of the present invention, theactivator-support used in preparing the catalyst compositions of thisinvention comprises an ion-exchangeable activator-support, including butnot limited to silicate and aluminosilicate compounds or minerals,either with layered or non-layered structures, and combinations thereof.In another aspect of this invention, ion-exchangeable, layeredaluminosilicates such as pillared clays are used as activator-supports.When the acidic activator-support comprises an ion-exchangeableactivator-support, it can optionally be treated with at least oneelectron-withdrawing anion such as those disclosed herein, thoughtypically the ion-exchangeable activator-support is not treated with anelectron-withdrawing anion.

According to another aspect of the present invention, theactivator-support of this invention comprises clay minerals havingexchangeable cations and layers capable of expanding. Typical claymineral activator-supports include, but are not limited to,ion-exchangeable, layered aluminosilicates such as pillared clays.Although the term “support” is used, it is not meant to be construed asan inert component of the catalyst composition, but rather is to beconsidered an active part of the catalyst composition, because of itsintimate association with the dinuclear metallocene component.

According to another aspect of the present invention, the clay materialsof this invention encompass materials either in their natural state orthat have been treated with various ions by wetting, ion exchange, orpillaring. Typically, the clay material activator-support of thisinvention comprises clays that have been ion exchanged with largecations, including polynuclear, highly charged metal complex cations.However, the clay material activator-supports of this invention alsoencompass clays that have been ion exchanged with simple salts,including, but not limited to, salts of Al(III), Fe(II), Fe(III) andZn(II) with ligands such as halide, acetate, sulfate, nitrate, ornitrite.

According to another aspect of the present invention, activator-supportcomprises a pillared clay. The term “pillared clay” is used to refer toclay materials that have been ion exchanged with large, typicallypolynuclear, highly charged metal complex cations. Examples of such ionsinclude, but are not limited to, Keggin ions which can have charges suchas 7+, various polyoxometallates, and other large ions. Thus, the termpillaring refers to a simple exchange reaction in which the exchangeablecations of a clay material are replaced with large, highly charged ions,such as Keggin ions. These polymeric cations are then immobilized withinthe interlayers of the clay and when calcined are converted to metaloxide “pillars,” effectively supporting the clay layers as column-likestructures. Thus, once the clay is dried and calcined to produce thesupporting pillars between clay layers, the expanded lattice structureis maintained and the porosity is enhanced. The resulting pores can varyin shape and size as a function of the pillaring material and the parentclay material used. Examples of pillaring and pillared clays are foundin: T. J. Pinnavaia, Science 220 (4595), 365-371 (1983); J. M. Thomas,Intercalation Chemistry, (S. Whittington and A. Jacobson, eds.) Ch. 3,pp. 55-99, Academic Press, Inc., (1972); U.S. Pat. No. 4,452,910; U.S.Pat. No. 5,376,611; and U.S. Pat. No. 4,060,480; the disclosures ofwhich are incorporated herein by reference in their entirety.

The pillaring process utilizes clay minerals having exchangeable cationsand layers capable of expanding. Any pillared clay that can enhance thepolymerization of olefins in the catalyst composition of the presentinvention can be used. Therefore, suitable clay minerals for pillaringinclude, but are not limited to, allophanes; smectites, bothdioctahedral (Al) and tri-octahedral (Mg) and derivatives thereof suchas montmorillonites (bentonites), nontronites, hectorites, or laponites;halloysites; vermiculites; micas; fluoromicas; chlorites; mixed-layerclays; the fibrous clays including but not limited to sepiolites,attapulgites, and palygorskites; a serpentine clay; illite; laponite;saponite; and any combination thereof. In one aspect, the pillared clayactivator-support comprises bentonite or montmorillonite. The principalcomponent of bentonite is montmorillonite.

The pillared clay can be pretreated if desired. For example, a pillaredbentonite is pretreated by drying at about 300° C. under an inertatmosphere, typically dry nitrogen, for about 3 hours, before beingadded to the polymerization reactor. Although an exemplary pretreatmentis described herein, it should be understood that the preheating can becarried out at many other temperatures and times, including anycombination of temperature and time steps, all of which are encompassedby this invention.

The activator-support used to prepare the catalyst compositions of thepresent invention can be combined with other inorganic supportmaterials, including, but not limited to, zeolites, inorganic oxides,phosphated inorganic oxides, and the like. In one aspect, typicalsupport materials that are used include, but are not limited to, silica,silica-alumina, alumina, titania, zirconia, magnesia, boria, thoria,aluminophosphate, aluminum phosphate, silica-titania, coprecipitatedsilica/titania, mixtures thereof, or any combination thereof.

According to yet another aspect of the present invention, one or more ofthe dinuclear metallocene compounds can be precontacted with an olefinmonomer and an organoaluminum compound for a first period of time priorto contacting this mixture with the activator-support. Once theprecontacted mixture of the metallocene compound(s), olefin monomer, andorganoaluminum compound is contacted with the activator-support, thecomposition further comprising the activator-support is termed the“postcontacted” mixture. The postcontacted mixture can be allowed toremain in further contact for a second period of time prior to beingcharged into the reactor in which the polymerization process will becarried out.

Organoaluminum Compounds

In one aspect, organoaluminum compounds that can be used with thepresent invention include, but are not limited to, compounds having theformula:(R²)₃Al;where R² is an aliphatic group having from 2 to 6 carbon atoms. Forexample, R² can be ethyl, propyl, butyl, hexyl, or isobutyl.

Other organoaluminum compounds which can be used in accordance with thepresent invention include, but are not limited to, compounds having theformula:A(X⁵)_(m)(X⁶)_(3-m),where X⁵ is a hydrocarbyl; X⁶ is an alkoxide or an aryloxide, a halide,or a hydride; and m is from 1 to 3, inclusive.

In one aspect, X⁵ is a hydrocarbyl having from 1 to about 20 carbonatoms. In another aspect of the present invention, X⁵ is an alkyl havingfrom 1 to 10 carbon atoms. For example, X⁵ can be ethyl, propyl,n-butyl, sec-butyl, isobutyl, or hexyl, and the like, in yet anotheraspect of the present invention.

According to one aspect of the present invention, X⁶ is an alkoxide oran aryloxide, any one of which has from 1 to 20 carbon atoms, a halide,or a hydride. In another aspect of the present invention, X⁶ is selectedindependently from fluorine or chlorine. Yet, in another aspect, X⁶ ischlorine.

In the formula, Al(X⁵)_(m)(X⁶)_(3-m), m is a number from 1 to 3,inclusive, and typically, m is 3. The value of m is not restricted to bean integer; therefore, this formula includes sesquihalide compounds orother organoaluminum cluster compounds.

Examples of organoaluminum compounds suitable for use in accordance withthe present invention include, but are not limited to, trialkylaluminumcompounds, dialkylaluminium halide compounds, dialkylaluminum alkoxidecompounds, dialkylaluminum hydride compounds, and combinations thereof.Specific non-limiting examples of suitable organoaluminum compoundsinclude trimethylaluminum (TMA), triethylaluminum (TEA),tripropylaluminum, diethylaluminum ethoxide, tributylaluminum,diisobutylaluminum hydride, triisobutylaluminum, diethylaluminumchloride, and the like, or combinations thereof.

The present invention contemplates precontacting at least one dinuclearmetallocene compound with at least one organoaluminum compound and anolefin monomer to form a precontacted mixture, prior to contacting thisprecontacted mixture with the activator-support to form a catalystcomposition. When the catalyst composition is prepared in this manner,typically, though not necessarily, a portion of the organoaluminumcompound is added to the precontacted mixture and another portion of theorganoaluminum compound is added to the postcontacted mixture preparedwhen the precontacted mixture is contacted with the solid oxideactivator-support. However, the entire organoaluminum compound can beused to prepare the catalyst composition in either the precontacting orpostcontacting step. Alternatively, all the catalyst components arecontacted in a single step.

Further, more than one organoaluminum compound can be used in either theprecontacting or the postcontacting step. When an organoaluminumcompound is added in multiple steps, the amounts of organoaluminumcompound disclosed herein include the total amount of organoaluminumcompound used in both the precontacted and postcontacted mixtures, andany additional organoaluminum compound added to the polymerizationreactor. Therefore, total amounts of organoaluminum compounds aredisclosed regardless of whether a single organoaluminum compound or morethan one organoaluminum compound is used.

Aluminoxane Compounds

The present invention further provides a catalyst composition which cancomprise an aluminoxane compound. As used herein, the term “aluminoxane”refers to aluminoxane compounds, compositions, mixtures, or discretespecies, regardless of how such aluminoxanes are prepared, formed orotherwise provided. For example, a catalyst composition comprising analuminoxane compound can be prepared in which aluminoxane is provided asthe poly(hydrocarbyl aluminum oxide), or in which aluminoxane isprovided as the combination of an aluminum alkyl compound and a sourceof active protons such as water. Aluminoxanes are also referred to aspoly(hydrocarbyl aluminum oxides) or organoaluminoxanes.

The other catalyst components typically are contacted with thealuminoxane in a saturated hydrocarbon compound solvent, though anysolvent that is substantially inert to the reactants, intermediates, andproducts of the activation step can be used. The catalyst compositionformed in this manner is collected by any suitable method, for example,by filtration. Alternatively, the catalyst composition is introducedinto the polymerization reactor without being isolated.

The aluminoxane compound of this invention can be an oligomeric aluminumcompound comprising linear structures, cyclic structures, or cagestructures, or mixtures of all three. Cyclic aluminoxane compoundshaving the formula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and p is an integer from 3 to 20, are encompassed by thisinvention. The AlRO moiety shown here also constitutes the repeatingunit in a linear aluminoxane. Thus, linear aluminoxanes having theformula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and q is an integer from 1 to 50, are also encompassed by thisinvention.

Further, aluminoxanes can have cage structures of the formula R^(t)_(5r+α)R^(b) _(r−α)Al_(4r)O_(3r), wherein R^(t) is a terminal linear orbranched alkyl group having from 1 to 10 carbon atoms; R^(b) is abridging linear or branched alkyl group having from 1 to 10 carbonatoms; r is 3 or 4; and α is equal to n_(Al(3))−n_(O(2))+n_(O(4)),wherein n_(Al(3)) is the number of three coordinate aluminum atoms,n_(O(2)) is the number of two coordinate oxygen atoms, and n_(O(4)) isthe number of 4 coordinate oxygen atoms.

Thus, aluminoxanes which can be employed in the catalyst compositions ofthe present invention are represented generally by formulas such as(R—Al—O)_(p), R(R—Al—O)_(q)AlR₂, and the like. In these formulas, the Rgroup is typically a linear or branched C₁-C₆ alkyl, such as methyl,ethyl, propyl, butyl, pentyl, or hexyl. Examples of aluminoxanecompounds that can be used in accordance with the present inventioninclude, but are not limited to, methylaluminoxane, ethylaluminoxane,n-propylaluminoxane, iso-propylaluminoxane, n-butylaluminoxane,t-butyl-aluminoxane, sec-butylaluminoxane, iso-butylaluminoxane,1-pentylaluminoxane, 2-pentylaluminoxane, 3-pentylaluminoxane,isopentylaluminoxane, neopentylaluminoxane, and the like, or anycombination thereof. Methyl aluminoxane, ethyl aluminoxane, and isobutylaluminoxane are prepared from trimethylaluminum, triethylaluminum, ortriisobutylaluminum, respectively, and sometimes are referred to aspoly(methyl aluminum oxide), poly(ethyl aluminum oxide), andpoly(isobutyl aluminum oxide), respectively. It is also within the scopeof the invention to use an aluminoxane in combination with atrialkylaluminum, such as that disclosed in U.S. Pat. No. 4,794,096,incorporated herein by reference in its entirety.

The present invention contemplates many values of p and q in thealuminoxane formulas (R—Al—O)_(p) and R(R—Al—O)_(q)AlR₂, respectively.Is some aspects, p and q are at least 3. However, depending upon how theorganoaluminoxane is prepared, stored, and used, the value of p and qcan vary within a single sample of aluminoxane, and such combinations oforganoaluminoxanes are contemplated herein.

In preparing a catalyst composition containing an aluminoxane, the molarratio of the total moles of aluminum in the aluminoxane (oraluminoxanes) to the total moles of dinuclear metallocene compound (orcompounds) in the composition is generally between about 1:10 and about100,000:1. In another aspect, the molar ratio is in a range from about5:1 to about 15,000:1. Optionally, aluminoxane can be added to apolymerization zone in ranges from about 0.01 mg/L to about 1000 mg/L,from about 0.1 mg/L to about 100 mg/L, or from about 1 mg/L to about 50mg/L.

Organoaluminoxanes can be prepared by various procedures. Examples oforganoaluminoxane preparations are disclosed in U.S. Pat. Nos. 3,242,099and 4,808,561, the disclosures of which are incorporated herein byreference in their entirety. For example, water in an inert organicsolvent can be reacted with an aluminum alkyl compound, such as (R²)₃Al,to form the desired organoaluminoxane compound. While not intending tobe bound by this statement, it is believed that this synthetic methodcan afford a mixture of both linear and cyclic R—Al—O aluminoxanespecies, both of which are encompassed by this invention. Alternatively,organoaluminoxanes are prepared by reacting an aluminum alkyl compound,such as (R²)₃Al with a hydrated salt, such as hydrated copper sulfate,in an inert organic solvent.

Organoboron/Organoborate Compounds

According to another aspect of the present invention, a catalystcomposition comprising organoboron or organoborate compounds isprovided. Such compounds include neutral boron compounds, borate salts,and the like, or combinations thereof. For example, fluoroorgano boroncompounds and fluoroorgano borate compounds are contemplated.

Any fluoroorgano boron or fluoroorgano borate compound can be utilizedwith the present invention. Examples of fluoroorgano borate compoundsthat can be used in the present invention include, but are not limitedto, fluorinated aryl borates such as N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and the like, ormixtures thereof. Examples of fluoroorgano boron compounds that can beused as co-catalysts in the present invention include, but are notlimited to, tris(pentafluorophenyl)boron,tris[3,5-bis(trifluoromethyl)phenyl]boron, and the like, or mixturesthereof. Although not intending to be bound by the following theory,these examples of fluoroorgano borate and fluoroorgano boron compounds,and related compounds, are thought to form “weakly-coordinating” anionswhen combined with organometal or metallocene compounds, as disclosed inU.S. Pat. No. 5,919,983, the disclosure of which is incorporated hereinby reference in its entirety. Applicants also contemplate the use ofdiboron, or bis-boron, compounds or other bifunctional compoundscontaining two or more boron atoms in the chemical structure, such asdisclosed in J. Am. Chem. Soc., 2005, 127, pp. 14756-14768, the contentof which is incorporated herein by reference in its entirety.

Generally, any amount of organoboron compound can be used. According toone aspect of this invention, the molar ratio of the total moles oforganoboron or organoborate compound (or compounds) to the total molesof dinuclear metallocene compound (or compounds) in the catalystcomposition is in a range from about 0.1:1 to about 15:1. Typically, theamount of the fluoroorgano boron or fluoroorgano borate compound used asa co-catalyst for the dinuclear metallocene is from about 0.5 moles toabout 10 moles of boron/borate compound per mole of dinuclearmetallocene compound. According to another aspect of this invention, theamount of fluoroorgano boron or fluoroorgano borate compound is fromabout 0.8 moles to about 5 moles of boron/borate compound per mole ofdinuclear metallocene compound.

Ionizing Ionic Compounds

The present invention further provides a catalyst composition comprisingan ionizing ionic compound. An ionizing ionic compound is an ioniccompound that can function as a co-catalyst to enhance the activity ofthe catalyst composition. While not intending to be bound by theory, itis believed that the ionizing ionic compound is capable of reacting witha metallocene compound and converting the metallocene into one or morecationic metallocene compounds, or incipient cationic metallocenecompounds. Again, while not intending to be bound by theory, it isbelieved that the ionizing ionic compound can function as an ionizingcompound by completely or partially extracting an anionic ligand,possibly a non-alkadienyl ligand such as X¹ or X², from the metallocene.However, the ionizing ionic compound is an activator regardless ofwhether it is ionizes the dinuclear metallocene, abstracts an X¹ or X²ligand in a fashion as to form an ion pair, weakens the metal-X¹ ormetal-X² bond in the dinuclear metallocene, simply coordinates to an X¹or X² ligand, or activates the metallocene by some other mechanism.

Further, it is not necessary that the ionizing ionic compound activatethe metallocene compounds only. The activation function of the ionizingionic compound can be evident in the enhanced activity of catalystcomposition as a whole, as compared to a catalyst composition that doesnot contain an ionizing ionic compound.

Examples of ionizing ionic compounds include, but are not limited to,the following compounds: tri(n-butyl)ammonium tetrakis(p-tolyl)borate,tri(n-butyl) ammonium tetrakis(m-tolyl)borate, tri(n-butyl)ammoniumtetrakis(2,4-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis(3,5-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(p-tolyl)borate, N,N-dimethylanilinium tetrakis(m-tolyl)borate,N,N-dimethylanilinium tetrakis(2,4-dimethylphenyl)borate,N,N-dimethylanilinium tetrakis(3,5-dimethylphenyl)borate,N,N-dimethylanilinium tetrakis[3,5-bis(trifluoro-methyl)phenyl]borate,N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,triphenylcarbenium tetrakis(p-tolyl)borate, triphenylcarbeniumtetrakis(m-tolyl)borate, triphenylcarbeniumtetrakis(2,4-dimethylphenyl)borate, triphenylcarbeniumtetrakis(3,5-dimethylphenyl)borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, tropylium tetrakis(p-tolyl)borate,tropylium tetrakis(m-tolyl)borate, tropyliumtetrakis(2,4-dimethylphenyl)borate, tropyliumtetrakis(3,5-dimethylphenyl)borate, tropyliumtetrakis[3,5-bis(trifluoro-methyl)phenyl]borate, tropyliumtetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, lithium tetraphenylborate, lithiumtetrakis(p-tolyl)borate, lithium tetrakis(m-tolyl)borate, lithiumtetrakis(2,4-dimethylphenyl)borate, lithiumtetrakis(3,5-dimethylphenyl)borate, lithium tetrafluoroborate, sodiumtetrakis(pentafluorophenyl)borate, sodium tetraphenylborate, sodiumtetrakis(p-tolyl)borate, sodium tetrakis(m-tolyl)borate, sodiumtetrakis(2,4-dimethylphenyl)borate, sodiumtetrakis(3,5-dimethylphenyl)borate, sodium tetrafluoroborate, potassiumtetrakis-(pentafluorophenyl)borate, potassium tetraphenylborate,potassium tetrakis(p-tolyl)borate, potassium tetrakis(m-tolyl)borate,potassium tetrakis(2,4-dimethyl-phenyl)borate, potassiumtetrakis(3,5-dimethylphenyl)borate, potassium tetrafluoro-borate,lithium tetrakis(pentafluorophenyl)aluminate, lithiumtetraphenylaluminate, lithium tetrakis(p-tolyl)aluminate, lithiumtetrakis(m-tolyl)aluminate, lithiumtetrakis(2,4-dimethylphenyl)aluminate, lithiumtetrakis(3,5-dimethylphenyl)aluminate, lithium tetrafluoroaluminate,sodium tetrakis(pentafluoro-phenyl)aluminate, sodiumtetraphenylaluminate, sodium tetrakis(p-tolyl)aluminate, sodiumtetrakis(m-tolyl)aluminate, sodiumtetrakis(2,4-dimethylphenyl)aluminate, sodiumtetrakis(3,5-dimethylphenyl)aluminate, sodium tetrafluoroaluminate,potassium tetrakis(pentafluorophenyl)aluminate, potassiumtetraphenylaluminate, potassium tetrakis(p-tolyl)aluminate, potassiumtetrakis(m-tolyl)aluminate, potassiumtetrakis(2,4-dimethylphenyl)aluminate, potassium tetrakis(3,5-dimethylphenyl)aluminate, potassium tetrafluoroaluminate, and thelike, or combinations thereof. Ionizing ionic compounds useful in thisinvention are not limited to these; other examples of ionizing ioniccompounds are disclosed in U.S. Pat. Nos. 5,576,259 and 5,807,938, thedisclosures of which are incorporated herein by reference in theirentirety.

Olefin Monomers

Unsaturated reactants that can be employed with catalyst compositionsand polymerization processes of this invention typically include olefincompounds having from about 2 to 30 carbon atoms per molecule and havingat least one olefinic double bond. This invention encompasseshomopolymerization processes using a single olefin such as ethylene orpropylene, as well as copolymerization reactions with at least onedifferent olefinic compound. The resulting copolymers generally containa major amount of ethylene (>50 mole percent) and a minor amount ofcomonomer (<50 mole percent), though this is not a requirement. Thecomonomers that can be copolymerized with ethylene often have from 3 to20 carbon atoms in their molecular chain.

Acyclic, cyclic, polycyclic, terminal (α), internal, linear, branched,substituted, unsubstituted, functionalized, and non-functionalizedolefins can be employed in this invention. For example, typicalunsaturated compounds that can be polymerized with the catalystcompositions of this invention include, but are not limited to,ethylene, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutylene,1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,2-hexene, 3-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene,the four normal octenes, the four normal nonenes, the five normaldecenes, and the like, or mixtures of two or more of these compounds.Cyclic and bicyclic olefins, including but not limited to, cyclopentene,cyclohexene, norbornylene, norbornadiene, and the like, can also bepolymerized as described above. Styrene can also be employed as amonomer.

When a copolymer is desired, the monomer can be, for example, ethyleneor propylene, which is copolymerized with a comonomer. Examples ofolefin comonomers include, but are not limited to, 1-butene, 2-butene,3-methyl-1-butene, isobutylene, 1-pentene, 2-pentene,3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 2-hexene,3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, 1-octene, and thelike. According to one aspect of the present invention, the comonomer isselected from 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, orstyrene.

Generally, the amount of comonomer introduced into a reactor zone toproduce the copolymer is from about 0.01 to about 50 weight percent ofthe comonomer based on the total weight of the monomer and comonomer.According to another aspect of the present invention, the amount ofcomonomer introduced into a reactor zone is from about 0.01 to about 40weight percent comonomer based on the total weight of the monomer andcomonomer. In still another aspect, the amount of comonomer introducedinto a reactor zone is from about 0.1 to about 35 weight percentcomonomer based on the total weight of the monomer and comonomer. Yet,in another aspect, the amount of comonomer introduced into a reactorzone is from about 0.5 to about 20 weight percent comonomer based on thetotal weight of the monomer and comonomer.

While not intending to be bound by this theory, where branched,substituted, or functionalized olefins are used as reactants, it isbelieved that a steric hindrance can impede and/or slow thepolymerization process. Thus, branched and/or cyclic portion(s) of theolefin removed somewhat from the carbon-carbon double bond would not beexpected to hinder the reaction in the way that the same olefinsubstituents situated more proximate to the carbon-carbon double bondmight. According to one aspect of the present invention, at least onemonomer/reactant is ethylene, so the polymerizations are either ahomopolymerization involving only ethylene, or copolymerizations with adifferent acyclic, cyclic, terminal, internal, linear, branched,substituted, or unsubstituted olefin. In addition, the catalystcompositions of this invention can be used in the polymerization ofdiolefin compounds including, but not limited to, 1,3-butadiene,isoprene, 1,4-pentadiene, and 1,5-hexadiene.

Preparation of the Catalyst Composition

In one aspect, the present invention encompasses a catalyst compositioncomprising a contact product of a dinuclear metallocene compound and anactivator-support. Such a composition can further comprise anorganoaluminum compound. Additionally, this catalyst composition canfurther comprise at least one optional co-catalyst, wherein the at leastone optional co-catalyst is at least one aluminoxane compound, at leastone organozinc compound, at least one organoboron or organoboratecompound, at least one ionizing ionic compound, or any combinationthereof. In another aspect, a catalyst composition is provided whichcomprises the contact product of at least one dinuclear metallocenecompound and at least one compound selected from at least onealuminoxane compound, at least one organozinc compound, at least oneorganoboron or organoborate compound, at least one ionizing ioniccompound, or any combination thereof.

This invention further encompasses methods of making these catalystcompositions, such as, for example, contacting the respective catalystcomponents in any order or sequence.

The at least one dinuclear metallocene compound can be precontacted withan olefinic monomer if desired, not necessarily the olefin monomer to bepolymerized, and an organoaluminum compound for a first period of timeprior to contacting this precontacted mixture with an activator-support.The first period of time for contact, the precontact time, between themetallocene compound or compounds, the olefinic monomer, and theorganoaluminum compound typically ranges from a time period of about 0.1hour to about 24 hours, for example, from about 0.1 to about 1 hour.Precontact times from about 10 minutes to about 30 minutes are alsoemployed.

Alternatively, the precontacting process is carried out in multiplesteps, rather than a single step, in which multiple mixtures areprepared, each comprising a different set of catalyst components. Forexample, at least two catalyst components are contacted forming a firstmixture, followed by contacting the first mixture with at least oneother catalyst component forming a second mixture, and so forth.

Multiple precontacting steps can be carried out in a single vessel or inmultiple vessels. Further, multiple precontacting steps can be carriedout in series (sequentially), in parallel, or a combination thereof. Forexample, a first mixture of two catalyst components can be formed in afirst vessel, a second mixture comprising the first mixture plus oneadditional catalyst component can be formed in the first vessel or in asecond vessel, which is typically placed downstream of the first vessel.

In another aspect, one or more of the catalyst components can be splitand used in different precontacting treatments. For example, part of acatalyst component is fed into a first precontacting vessel forprecontacting with at least one other catalyst component, while theremainder of that same catalyst component is fed into a secondprecontacting vessel for precontacting with at least one other catalystcomponent, or is fed directly into the reactor, or a combinationthereof. The precontacting can be carried out in any suitable equipment,such as tanks, stirred mix tanks, various static mixing devices, aflask, a vessel of any type, or combinations of these apparatus.

In another aspect of this invention, the various catalyst components(for example, dinuclear metallocene, activator-support, organoaluminumco-catalyst, and optionally an unsaturated hydrocarbon) are contacted inthe polymerization reactor simultaneously while the polymerizationreaction is proceeding. Alternatively, any two or more of these catalystcomponents can be precontacted in a vessel prior to entering thereaction zone. This precontacting step can be continuous, in which theprecontacted product is fed continuously to the reactor, or it can be astepwise or batchwise process in which a batch of precontacted productis added to make a catalyst composition. This precontacting step can becarried out over a time period that can range from a few seconds to asmuch as several days, or longer. In this aspect, the continuousprecontacting step generally lasts from about 1 second to about 1 hour.In another aspect, the continuous precontacting step lasts from about 10seconds to about 45 minutes, or from about 1 minute to about 30 minutes.

Once the precontacted mixture of the metallocene compound, olefinmonomer, and organoaluminum co-catalyst is contacted with theactivator-support, this composition (with the addition of theactivator-support) is termed the “postcontacted mixture.” Thepostcontacted mixture optionally remains in contact for a second periodof time, the postcontact time, prior to initiating the polymerizationprocess. Postcontact times between the precontacted mixture and theactivator-support generally range from about 0.1 hour to about 24 hours.In a further aspect, the postcontact time is in a range from about 0.1hour to about 1 hour. The precontacting step, the postcontacting step,or both, can increase the productivity of the polymer as compared to thesame catalyst composition that is prepared without precontacting orpostcontacting. However, neither a precontacting step nor apostcontacting step is required.

The postcontacted mixture can be heated at a temperature and for a timeperiod sufficient to allow adsorption, impregnation, or interaction ofprecontacted mixture and the activator-support, such that a portion ofthe components of the precontacted mixture is immobilized, adsorbed, ordeposited thereon. Where heating is employed, the postcontacted mixturegenerally is heated to a temperature of from between about 0° F. toabout 150° F., or from about 40° F. to about 95° F.

According to one aspect of this invention, the molar ratio of the molesof dinuclear metallocene compound to the moles of organoaluminumcompound in a catalyst composition generally is in a range from about1:1 to about 1:10,000. In another aspect, the molar ratio is in a rangefrom about 1:1 to about 1:1,000. Yet, in another aspect, the molar ratioof the moles of dinuclear metallocene compound to the moles oforganoaluminum compound is in a range from about 1:1 to about 1:100.These molar ratios reflect the ratio of total moles of dinuclearmetallocene compound or compounds to the total amount of organoaluminumcompound (or compounds) in both the precontacted mixture and thepostcontacted mixture combined, if precontacting and/or postcontactingsteps are employed.

When a precontacting step is used, the molar ratio of the total moles ofolefin monomer to total moles of dinuclear metallocene in theprecontacted mixture is typically in a range from about 1:10 to about100,000:1. Total moles of each component are used in this ratio toaccount for aspects of this invention where more than one olefin monomerand/or more than dinuclear metallocene is employed. Further, this molarratio can be in a range from about 10:1 to about 1,000:1 in anotheraspect of the invention.

Generally, the weight ratio of organoaluminum compound toactivator-support is in a range from about 10:1 to about 1:1000. If morethan one organoaluminum compound and/or more than one activator-supportis employed, this ratio is based on the total weight of each respectivecomponent. In another aspect, the weight ratio of the organoaluminumcompound to the activator-support is in a range from about 3:1 to about1:100, or from about 1:1 to about 1:50.

In some aspects of this invention, the weight ratio of dinuclearmetallocene to activator-support is in a range from about 1:1 to about1:1,000,000. If more than one dinuclear metallocene and/or more than oneactivator-support is employed, this ratio is based on the total weightof each respective component. In another aspect, this weight ratio is ina range from about 1:5 to about 1:100,000, or from about 1:10 to about1:10,000. Yet, in another aspect, the weight ratio of the dinuclearmetallocene compound to the activator-support is in a range from about1:20 to about 1:1000.

According to some aspects of this invention, aluminoxane compounds arenot required to form the catalyst composition. Thus, the polymerizationproceeds in the absence of aluminoxanes. Accordingly, the presentinvention can use, for example, organoaluminum compounds and anactivator-support in the absence of aluminoxanes. While not intending tobe bound by theory, it is believed that the organoaluminum compoundlikely does not activate the metallocene catalyst in the same manner asan organoaluminoxane compound.

Additionally, in some aspects, organoboron and organoborate compoundsare not required to form a catalyst composition of this invention.Nonetheless, aluminoxanes, organozinc compounds, organoboron ororganoborate compounds, ionizing ionic compounds, or combinationsthereof can be used in other catalyst compositions contemplated by andencompassed within the present invention. Hence, co-catalysts such asaluminoxanes, organozinc compounds, organoboron or organoboratecompounds, ionizing ionic compounds, or combinations thereof, can beemployed with the dinuclear metallocene compound, either in the presenceor in the absence of an activator-support, and either in the presence orin the absence of an organoaluminum compound.

Catalyst compositions of the present invention generally have a catalystactivity greater than about 100 grams of polyethylene per gram ofactivator-support per hour (abbreviated gP/(gAS·hr)). In another aspect,the catalyst activity is greater than about 150, greater than about 200,or greater than about 250 gP/(gAS·hr). In still another aspect, catalystcompositions of this invention are characterized by having a catalystactivity greater than about 500, greater than about 1000, or greaterthan about 1500 gP/(gAS·hr). Yet, in another aspect, the catalystactivity is greater than about 2000 gP/(gAS·hr). This activity ismeasured under slurry polymerization conditions using isobutane as thediluent, at a polymerization temperature of about 90° C. and an ethylenepressure of about 550 psig.

Other aspects of the present invention do not require anactivator-support. These catalyst compositions comprise a contactproduct of at least one dinuclear metallocene compound and at least onecompound selected from at least one aluminoxane compound, at least oneorganozinc compound, at least one organoboron or organoborate compound,at least one ionizing ionic compound, or any combination thereof. Suchcatalyst compositions of the present invention generally have catalystactivities greater than about 100 grams of polyethylene per hour pergram of the respective aluminoxane compound, organozinc compound,organoboron or organoborate compound, ionizing ionic compound, orcombination thereof. In another aspect, the catalyst activity is greaterthan about 250, or greater than about 500 grams of polyethylene per hourper gram of the respective aluminoxane compound, organozinc compound,organoboron or organoborate compound, ionizing ionic compound, orcombination thereof. Yet, in another aspect, the catalyst activity isgreater than about 1000, or greater than about 2000 grams ofpolyethylene per hour.

As discussed above, any combination of the dinuclear metallocenecompound, the activator-support, the organoaluminum compound, and theolefin monomer, can be precontacted in some aspects of this invention.When any precontacting occurs with an olefinic monomer, it is notnecessary that the olefin monomer used in the precontacting step be thesame as the olefin to be polymerized. Further, when a precontacting stepamong any combination of the catalyst components is employed for a firstperiod of time, this precontacted mixture can be used in a subsequentpostcontacting step between any other combination of catalyst componentsfor a second period of time. For example, the dinuclear metallocenecompound, the organoaluminum compound, and 1-hexene can be used in aprecontacting step for a first period of time, and this precontactedmixture then can be contacted with the activator-support to form apostcontacted mixture that is contacted for a second period of timeprior to initiating the polymerization reaction. For example, the firstperiod of time for contact, the precontact time, between any combinationof the metallocene compound, the olefinic monomer, theactivator-support, and the organoaluminum compound can be from about 0.1hour to about 24 hours, from about 0.1 to about 1 hour, or from about 10minutes to about 30 minutes. The postcontacted mixture optionally isallowed to remain in contact for a second period of time, thepostcontact time, prior to initiating the polymerization process.According to one aspect of this invention, postcontact times between theprecontacted mixture and any remaining catalyst components is from about0.1 hour to about 24 hours, or from about 0.1 hour to about 1 hour.

Polymerization Process

Catalyst compositions of the present invention can be used to polymerizeolefins to form homopolymers or copolymers. One such process forpolymerizing olefins in the presence of a catalyst composition of thepresent invention comprises contacting the catalyst composition with atleast one olefin monomer and optionally at least one olefin comonomerunder polymerization conditions to produce a polymer or copolymer,wherein the catalyst composition comprises a contact product of at leastone dinuclear metallocene compound and at least one activator-support.The at least one dinuclear metallocene compound is selected from thefollowing formula:

wherein:

X¹ and X² independently are a halide or a substituted or unsubstitutedaliphatic, aromatic, or cyclic group, or a combination thereof;

X³ is a substituted or unsubstituted cyclopentadienyl, indenyl, orfluorenyl group, any substituents on X³ independently are a hydrogenatom or a substituted or unsubstituted alkyl or alkenyl group;

X⁴ is a substituted cyclopentadienyl, indenyl, or fluorenyl group, anysubstituents on X⁴ other than an alkenyl linking group independently area hydrogen atom or a substituted or unsubstituted alkyl or alkenylgroup;

M is Zr, Hf, or Ti;

R^(X), R^(Y), and R^(Z) independently are a hydrogen atom, or asubstituted or unsubstituted aliphatic, aromatic, or cyclic group, or acombination thereof; and

n is an integer in a range from 0 to 12, inclusive;

with the proviso that the integer n is not equal to 0 when both X¹ andX² are chlorine atoms, both X³ and X⁴ are cyclopentadienyl groups,R^(X), R^(Y), and R^(Z) are each hydrogen atoms, and M is Ti.

The catalyst compositions of the present invention are intended for anyolefin polymerization method using various types of polymerizationreactors. As used herein, “polymerization reactor” includes anypolymerization reactor capable of polymerizing olefin monomers toproduce homopolymers or copolymers. Such homopolymers and copolymers arereferred to as resins or polymers. The various types of reactors includethose that may be referred to as batch, slurry, gas-phase, solution,high pressure, tubular or autoclave reactors. Gas phase reactors maycomprise fluidized bed reactors or staged horizontal reactors. Slurryreactors may comprise vertical or horizontal loops. High pressurereactors may comprise autoclave or tubular reactors. Reactor types caninclude batch or continuous processes. Continuous processes could useintermittent or continuous product discharge. Processes may also includepartial or full direct recycle of un-reacted monomer, un-reactedcomonomer, and/or diluent.

Polymerization reactor systems of the present invention may comprise onetype of reactor in a system or multiple reactors of the same ordifferent type. Production of polymers in multiple reactors may includeseveral stages in at least two separate polymerization reactorsinterconnected by a transfer device making it possible to transfer thepolymers resulting from the first polymerization reactor into the secondreactor. The desired polymerization conditions in one of the reactorsmay be different from the operating conditions of the other reactors.Alternatively, polymerization in multiple reactors may include themanual transfer of polymer from one reactor to subsequent reactors forcontinued polymerization. Multiple reactor systems may include anycombination including, but not limited to, multiple loop reactors,multiple gas reactors, a combination of loop and gas reactors, multiplehigh pressure reactors or a combination of high pressure with loopand/or gas reactors. The multiple reactors may be operated in series orin parallel.

According to one aspect of the invention, the polymerization reactorsystem may comprise at least one loop slurry reactor comprising verticalor horizontal loops. Monomer, diluent, catalyst and optionally anycomonomer may be continuously fed to a loop reactor where polymerizationoccurs. Generally, continuous processes may comprise the continuousintroduction of a monomer, a catalyst, and a diluent into apolymerization reactor and the continuous removal from this reactor of asuspension comprising polymer particles and the diluent. Reactoreffluent may be flashed to remove the solid polymer from the liquidsthat comprise the diluent, monomer and/or comonomer. Varioustechnologies may be used for this separation step including but notlimited to, flashing that may include any combination of heat additionand pressure reduction; separation by cyclonic action in either acyclone or hydrocyclone; or separation by centrifugation.

A typical slurry polymerization process (also known as the particle formprocess), is disclosed, for example, in U.S. Pat. Nos. 3,248,179,4,501,885, 5,565,175, 5,575,979, 6,239,235, 6,262,191 and 6,833,415,each of which is incorporated by reference in its entirety herein.

Suitable diluents used in slurry polymerization include, but are notlimited to, the monomer being polymerized and hydrocarbons that areliquids under reaction conditions. Examples of suitable diluentsinclude, but are not limited to, hydrocarbons such as propane,cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, andn-hexane. Some loop polymerization reactions can occur under bulkconditions where no diluent is used. An example is polymerization ofpropylene monomer as disclosed in U.S. Pat. No. 5,455,314, which isincorporated by reference herein in its entirety.

According to yet another aspect of this invention, the polymerizationreactor may comprise at least one gas phase reactor. Such systems mayemploy a continuous recycle stream containing one or more monomerscontinuously cycled through a fluidized bed in the presence of thecatalyst under polymerization conditions. A recycle stream may bewithdrawn from the fluidized bed and recycled back into the reactor.Simultaneously, polymer product may be withdrawn from the reactor andnew or fresh monomer may be added to replace the polymerized monomer.Such gas phase reactors may comprise a process for multi-step gas-phasepolymerization of olefins, in which olefins are polymerized in thegaseous phase in at least two independent gas-phase polymerization zoneswhile feeding a catalyst-containing polymer formed in a firstpolymerization zone to a second polymerization zone. One type of gasphase reactor is disclosed in U.S. Pat. Nos. 5,352,749, 4588,790 and5,436,304, each of which is incorporated by reference in its entiretyherein.

According to still another aspect of the invention, a high pressurepolymerization reactor may comprise a tubular reactor or an autoclavereactor. Tubular reactors may have several zones where fresh monomer,initiators, or catalysts are added. Monomer may be entrained in an inertgaseous stream and introduced at one zone of the reactor. Initiators,catalysts, and/or catalyst components may be entrained in a gaseousstream and introduced at another zone of the reactor. The gas streamsmay be intermixed for polymerization. Heat and pressure may be employedappropriately to obtain optimal polymerization reaction conditions.

According to yet another aspect of the invention, the polymerizationreactor may comprise a solution polymerization reactor wherein themonomer is contacted with the catalyst composition by suitable stirringor other means. A carrier comprising an inert organic diluent or excessmonomer may be employed. If desired, the monomer may be brought in thevapor phase into contact with the catalytic reaction product, in thepresence or absence of liquid material. The polymerization zone ismaintained at temperatures and pressures that will result in theformation of a solution of the polymer in a reaction medium. Agitationmay be employed to obtain better temperature control and to maintainuniform polymerization mixtures throughout the polymerization zone.Adequate means are utilized for dissipating the exothermic heat ofpolymerization.

Polymerization reactors suitable for the present invention may furthercomprise any combination of at least one raw material feed system, atleast one feed system for catalyst or catalyst components, and/or atleast one polymer recovery system. Suitable reactor systems for thepresent invention may further comprise systems for feedstockpurification, catalyst storage and preparation, extrusion, reactorcooling, polymer recovery, fractionation, recycle, storage, loadout,laboratory analysis, and process control.

Conditions that are controlled for polymerization efficiency and toprovide resin properties include temperature, pressure and theconcentrations of various reactants. Polymerization temperature canaffect catalyst productivity, polymer molecular weight and molecularweight distribution. Suitable polymerization temperature may be anytemperature below the de-polymerization temperature according to theGibbs Free energy equation. Typically this includes from about 60° C. toabout 280° C., for example, and from about 70° C. to about 110° C.,depending upon the type of polymerization reactor.

Suitable pressures will also vary according to the reactor andpolymerization type. The pressure for liquid phase polymerizations in aloop reactor is typically less than 1000 psig. Pressure for gas phasepolymerization is usually at about 200 to 500 psig. High pressurepolymerization in tubular or autoclave reactors is generally run atabout 20,000 to 75,000 psig. Polymerization reactors can also beoperated in a supercritical region occurring at generally highertemperatures and pressures. Operation above the critical point of apressure/temperature diagram (supercritical phase) may offer advantages.

The concentration of various reactants can be controlled to produceresins with certain physical and mechanical properties. The proposedend-use product that will be formed by the resin and the method offorming that product determines the desired resin properties. Mechanicalproperties include tensile, flexural, impact, creep, stress relaxationand hardness tests. Physical properties include density, molecularweight, molecular weight distribution, melting temperature, glasstransition temperature, temperature melt of crystallization, density,stereoregularity, crack growth, long chain branching and rheologicalmeasurements.

The concentrations of monomer, co-monomer, hydrogen, co-catalyst,modifiers, and electron donors are important in producing these resinproperties. Comonomer is used to control product density. Hydrogen canbe used to control product molecular weight. Co-catalysts can be used toalkylate, scavenge poisons and control molecular weight. Modifiers canbe used to control product properties and electron donors affectstereoregularity. In addition, the concentration of poisons is minimizedbecause poisons impact the reactions and product properties.

The polymer or resin may be formed into various articles, including, butnot limited to, bottles, drums, toys, household containers, utensils,film products, drums, fuel tanks, pipes, geomembranes, and liners.Various processes may be used to form these articles, including, but notlimited to, blow molding, extrusion molding, rotational molding,thermoforming, cast molding and the like. After polymerization,additives and modifiers can be added to the polymer to provide betterprocessing during manufacturing and for desired properties in the endproduct. Additives include surface modifiers such as slip agents,antiblocks, tackifiers; antioxidants such as primary and secondaryantioxidants; pigments; processing aids such as waxes/oils andfluoroelastomers; and special additives such as fire retardants,antistats, scavengers, absorbers, odor enhancers, and degradationagents.

Homopolymers and copolymers of ethylene produced in accordance with thisinvention generally have a melt index from about 0.01 to about 100 g/10min. For example, a melt index in the range from about 0.1 to about 50g/10 min, or from about 0.5 to about 25 g/10 min, are contemplated insome aspects of this invention.

The density of ethylene-based polymers produced using one or moredinuclear metallocene compounds of the present invention typically fallswithin the range from about 0.88 to about 0.97 g/cc. In one aspect ofthis invention, the polymer density is in a range from about 0.90 toabout 0.95 g/cc. Yet, in another aspect, the density is generally in arange from about 0.91 to about 0.94 g/cc.

If the resultant polymer produced in accordance with the presentinvention is, for example, a polymer or copolymer of ethylene, it can beformed into various articles of manufacture. Such articles include, butare not limited to, molded products, household containers, utensils,film or sheet products, drums, fuel tanks, pipes, geomembranes, liners,and the like. Various processes can be employed to form these articles.Non-limiting examples of these processes include injection molding, blowmolding, film extrusion, sheet extrusion, profile extrusion, and thelike. Additionally, additives and modifiers are often added to thesepolymers in order to provide beneficial polymer processing or end-useproduct attributes.

EXAMPLES

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, embodiments, modifications,and equivalents thereof which, after reading the description herein, maysuggest themselves to one of ordinary skill in the art without departingfrom the spirit of the present invention or the scope of the appendedclaims.

Nuclear Magnetic Resonance (NMR) spectra were obtained on a VarianMercury Plus 300 NMR spectrometer operating at 300 MHz for ¹H NMR (CDCl₃solvent, referenced against the peak of residual CHCl₃ at 7.24 ppm) and75 MHz for ¹³C NMR (CDCl₃ solvent, referenced against central line ofCHCl₃ at 77.00 ppm).

In addition to NMR, a thermal desorption mass spectrometry procedure(direct insertion probe mass spectrometry or DIPMS) was used tocharacterize and identify the dinuclear metallocene compounds in theexamples. The mass spectrometer had the following capabilities: 70 evelectron impact ionization, mass range from 35 to 1200 amu, direct probeinsertion accessory with maximum temperature to at least 650° C., andsoftware capable of integrating broad peaks typical of probe runs. Themethod was developed using a Finnigan™ TSQ 7000™ instrument, scan rangeof 35 to 1400 (1 second scan time), conventional thin wire (with loop attip) probe tips, source temperature of 180° C., 2×10-6 manifold vacuum,and Finnigan™ Excalibur™ software for peak integration and instrumentcontrol. Other instruments having comparable mass range and probecapabilities could be utilized.

In the DIPMS procedure, the sample is placed on the probe tip using amicro syringe. In practice, the smallest drop of sample which can betransferred to the probe usually gives the best results. After placingthe sample on the probe, it is allowed to stand for about 5-10 min toallow for evaporation of the bulk of the diluent/solvent containing thecompound of interest. Allowing the diluent/solvent to evaporate beforeinserting the probe into the instrument will, among other things, lessenthe chance that the drop will fall off of the tip during the insertionprocess. After inserting the probe, the temperature program and dataacquisition cycles begin. The temperature program used was 50° C. (hold1 min), 30° C./min temperature ramp, 650° C. final temperature (hold 5min). This program takes 26 minutes to complete. The filament was turnedon 0.5 min into the run and kept on until the completion of thetemperature program. After a couple of minutes to allow the probe tip tocool, the probe was removed from the instrument and the analysis cyclewas complete.

The Finnigan™ instrument had removable ion volumes; these were changedand cleaned after every two runs to minimize buildup of residue on thelens and other source components. The results are typically outputted asplots showing total ion current versus time.

Melt index (MI, g/10 min) was determined in accordance with ASTM D1238at 190° C. with a 2,160 gram weight.

High load melt index (HLMI, g/10 min) was determined in accordance withASTM D1238 at 190° C. with a 21,600 gram weight.

Polymer density was determined in grams per cubic centimeter (g/cc) on acompression molded sample, cooled at about 15° C. per hour, andconditioned for about 40 hours at room temperature in accordance withASTM D1505 and ASTM D1928, procedure C.

Melt theological characterizations were determined by suitable methods.For example, small-strain (10%) oscillatory shear measurements wereperformed on a Rheometrics Scientific, Inc. ARES rheometer usingparallel-plate geometry. All theological tests were performed at 190° C.

Molecular weights and molecular weight distributions were obtained usinga PL 220 SEC high temperature chromatography unit (Polymer Laboratories)with trichlorobenzene (TCB) as the solvent, with a flow rate of 1mL/minute at a temperature of 145° C. BHT(2,6-di-tert-butyl-4-methylphenol) at a concentration of 0.5 g/L wasused as a stabilizer in the TCB. An injection volume of 200 μL was usedwith a nominal polymer concentration of 1.5 mg/mL. Dissolution of thesample in stabilized TCB was carried out by heating at 150° C. for 5hours with occasional, gentle agitation. The columns used were threePLgel Mixed A LS columns (7.8×300 mm) and were calibrated with a broadlinear polyethylene standard (Phillips Marlex® BHB 5003) for which themolecular weight had been determined.

Molecular weight distributions and branch profiles were obtained throughsize exclusion chromatography (SEC) using an FTIR detector.Chromatographic conditions are those described above. However, thesample injection volume was 500 μL. Samples were introduced to the FTIRdetector via a heated transfer line and flow cell (KBr windows, 1 mmoptical path, and ca. 70 μL cell volume). The temperatures of thetransfer line and flow cell were kept at 143±1° C. and 140±1° C.,respectively. A Perkin Elmer FTIR spectrophotometer (PE 2000) equippedwith a narrow band mercury cadmium telluride (MCT) detector was used inthese studies.

All spectra were acquired using Perkin Elmer Timebase software.Background spectra of the TCB solvent were obtained prior to each run.All IR spectra were measured at 8 cm⁻¹ resolution (16 scans).Chromatograms were generated using the root mean square absorbance overthe 3000-2700 cm⁻¹ spectral region (i.e., FTIR serves as a concentrationdetector). Molecular weight calculations were made as previouslydescribed using a broad molecular weight polyethylene (PE) standard [seeJordens K, Wilkes G L, Janzen J, Rohlfing D C, Welch M B, Polymer 2000;41:7175]. Spectra from individual time slices of the chromatogram weresubsequently analyzed for comonomer branch levels using chemometrictechniques. All calibration spectra were taken at sample concentrationswhich far exceeded that needed for good signal to noise (i.e., >0.08mg/mL at the detector).

Branching content was determined as follows. Narrow molecular weight(weight-average molecular weight to number-average molecular weightratio (M_(w)/M_(n)) of about 1.1 to 1.3), solvent gradient fractions ofethylene 1-butene, ethylene 1-hexene, polyethylene homopolymers, and lowmolecular weight alkanes were used in calibration and verificationstudies. The total methyl content of these samples ranged from 1.4 to82.7 methyls per 1000 total carbons. Methyl content of samples wascalculated from M_(n) or measured using C-13 NMR spectroscopy. C-13 NMRspectra were obtained on 15 weight percent samples in TCB using a 500MHz Varian Unity Spectrometer run at 125° C. as previous described [seeRandall J C, Hsieh E T, NMR and Macromolecules; Sequence, Dynamic, andDomain Structure, ACS Symposium Series 247, J. C. Randall, Ed., AmericanChemical Society, Washington D.C., 1984.]. Methyl content per 1000carbons by NMR was obtained by multiplying (times 1000) the ratio oftotal methyl signals to total signal intensity.

A partial least squares (PLS) calibration curve was generated usingPirouette chemometric software (Infometrix) to correlate changes in theFTIR absorption spectra with calculated or NMR measured values formethyls/1000 total carbons for 25 samples. The FTIR absorption spectraused in the calibration model were made from co-added spectra collectedacross the whole sample. Only a portion of the spectral region (2996 and2836 cm⁻¹) was used in the calibration step in order to minimize theeffects of residual solvent absorption. Preprocessing of spectral dataincluded area normalization, taking the first derivative of the spectraand mean centering all data.

A four component calibration model was calculated and optimized usingthe process of cross validation (RSQ=0.999, SEV=0.7). The calibrationmodel was verified using 23 additional samples. The predicted versusactual values for the validation data showed excellent correlation(RSQ=0.987) and exhibited a root mean square error of prediction equalto +/−0.4 methyl groups per 1000 total carbon molecules.

Short chain branching levels were calculated by subtracting out methylchain end contributions. The amount of methyl chain ends were calculatedusing the equation Me_(ce)=C(2−V_(ce))/M_(s), where Me_(ce) is thenumber of methyl chain ends per 1000 total carbon molecules, C is aconstant equal to 14000, V_(ce) is the number of vinyl terminated chainends (e.g., 1 for chromium catalyzed resins), and M_(s) is the molecularweight calculated for a particular slice of the molecular weightdistribution.

Sulfated alumina was formed by a process wherein alumina waschemically-treated with a sulfate or bisulfate source. Such a sulfate orbisulfate source may include, for example, sulfuric acid, ammoniumsulfate, or ammonium bisulfate. In an exemplary procedure, a commercialalumina sold as W.R. Grace Alumina A was sulfated by impregnation withan aqueous solution containing about 15-20% (NH₄)₂SO₄ or H₂SO₄. Thissulfated alumina was calcined at 550° C. in air (240° C./hr ramp rate),with a 3 hr hold period at this temperature. Afterward, the sulfatedalumina was collected and stored under dry nitrogen, and was usedwithout exposure to the atmosphere.

Example 1 Synthesis ofCl₂Zr{eta-5-C₅H₄—[(CH₂)₃CH₃](eta-5-C₉H₆-1-(CH₂CH═CHCH₂)(1-eta-5-C₉H₆)eta-5-C₅H₄—[(CH₂)₃CH₃}ZrCl₂, C₄₀H₄₄Zr₂Cl₄ (DMET 1), usingolefin metathesis

DMET 1 is a nano-linked, dinuclear compound of the presented invention.It is produced using a single metallocene reactant and is, therefore, ahomonuclear compound. The reactant metallocene used to produce DMET 1 isn-butylcyclopentadienyl)(1-allylindenyl) zirconium dichloride, or{eta-5-C₅H₄-[(CH₂)₃CH₃] (eta-5-C₉H₆-1-(CH₂CH═CH₂)}ZrCl₂, C₂₁H₂₄ZrCl₂(abbreviated “MET 1”). The reaction scheme for this inventive example isillustrated below:

The MET 1 metallocene starting material can be prepared in accordancewith suitable methods. One such technique is described in U.S. Pat. No.7,226,886, the disclosure of which is incorporated herein by referencein its entirety.

Approximately 1 mg of bis(tricyclohexylphosphine)benzylidene ruthenium(IV) dichloride (Grubbs first generation metathesis catalyst) wascharged to a reactor under an inert nitrogen atmosphere. After about 108mg of MET 1 were charged to the reactor, approximately 1.5 mL ofbenzene-d6 were added via syringe. The reaction was allowed to proceedat ambient temperature. Initially, an amber solution resulted andethylene was released from the reaction mixture. As the reactionproceeded, the reaction mixture became a turbid yellow color. Afterabout 5 days, approximately 2 mL of benzene-d6 were then added to thereaction mixture. After 7 days, a sample of the reaction product wasremoved, and utilized in Example 2. Additionally, a sample of thereaction product was removed, and analyzed via 1H-NMR. Although theconversion to DMET 1 was slow, NMR showed the presence of the desireddinuclear compound, DMET 1. The NMR of MET 1 is shown in FIG. 1. Theterminal vinylic protons of MET 1 are located between about 5.0 to 5.5ppm. The relative reduction of these proton resonances demonstrates theconversion and metathesis of MET 1 to DMET 1.

After 11 days, approximately 3.75 mg of ruthenium catalyst in 1 mL ofbenzene-d6 were then added to the product remaining in the reactor.After a total of 40 days at a temperature of around 30° C., the solidreaction product was removed from the reactor. A sample of this reactionproduct was dissolved in D-chloroform to form a solution for analysis by¹H-NMR. NMR indicated the presence of the desired dinuclear compound,DMET 1, as illustrated in FIG. 2.

Example 2 Hydrolysis of DMET 1, C₄₀H₄₄Zr₂Cl₄, to the free ligand, C₂₂H₂₀

Although the conversion to DMET 1 was slow in Example 1, massspectrometry also indicated the presence of the desired dinuclearcompound, DMET 1. A portion of the reaction product after 7 days fromExample 1 was used as the starting material for Example 2.

A sample of the reaction product of Example 1 was placed in a vial andhydrolyzed using about 10 microliters of water in about 0.5 mL oftoluene. The metal was hydrolyzed to the free ligand(1,4-diindenylbutene-2; C₂₂H₂₀) and the ligands having the followingstructure were subsequently characterized:

This isomeric compound (C₂₂H₂₀) was analyzed using the thermaldesorption mass spectrometry procedure, DIPMS, outlined above. Asillustrated in FIG. 3, the prominent molecular ion observed wasconsistent with the expected molecular mass of about 284 Daltons of thefree ligand.

Examples 3-13 Polymerization Runs Using Catalyst Systems Based onDinuclear Metallocene DMET 1 and Metallocene MET 1

Dinuclear metallocene compounds of the present invention were used aspart of a catalyst system to polymerize olefins. All polymerizationswere conducted in a one-gallon stainless steel semi-batch reactor. Twoliters of isobutane and alkyl aluminum co-catalyst were used in allpolymerization experiments. The typical polymerization procedure wasconducted as follows: alkyl aluminum, the activator-support and themetallocene were added in order through a charge port while ventingisobutane vapor. The charge port was closed and about 2 liters ofisobutane were added. The contents of the reactor were stirred andheated to the desired run temperature, and ethylene was then introducedalong with the desired amount of hexene. Ethylene was fed on demand tomaintain the specified pressure for the specified length of thepolymerization run. The reactor was maintained and controlled at thedesired run temperature throughout the polymerization. Upon completion,the ethylene flow was stopped and the reactor pressure slowly ventedoff. The reactor was opened and the polymer product was collected anddried under vacuum at approximately 50° C. for at least two hours.

Table I summarizes the catalyst system formulations employed forExamples 3-13. In Examples 3-13, the dinuclear metallocene product ofExample 1 (DMET 1) and the reactant metallocene of Example 1 (MET 1)were compared. Ethylene/1-hexene copolymers were produced using thedinuclear metallocene product of Example 1, DMET 1, and the metallocenestarting material, MET 1. The specific polymerization conditionsemployed were a 30 minute run time, reaction temperature of 80° C., 450psig ethylene feed, and 45 grams of 1-hexene with 0.5 mmol oftriisobutylaluminum (TIBA) per 100 mg of sulfated alumina. The loadingof the metallocene (MET 1 or DMET 1) was varied from about 7 micromolesZr per gram of sulfated alumina to about 56 micromoles Zr per gram ofsulfated alumina.

The dinuclear metallocene compound, DMET 1, was supplied from a solutioncontaining about 14 mg of DMET 1 in about 14 mL of toluene. Thus, forinstance, Example 3 was conducted using a 2.5 mg loading of DMET 1 on100 mg of sulfated alumina (2.5 mL of DMET 1 in toluene solution), plus0.5 mL of 1.0 M TIBA in hexanes.

TABLE I Catalyst formulations containing DMET 1 and MET 1. mg mmol μmolExample Catalyst Catalyst Catalyst μmol Zr mg A-S Zr/g 3 DMET 1 2.50.00295 5.89 106 55.6 4 DMET 1 1.25 0.00147 2.94 105 28.0 5 DMET 1 0.630.00074 1.48 105 14.1 6 DMET 1 0.32 0.00038 0.75 101 7.5 7 DMET 1 1.250.00147 2.94 108 27.3 8 MET 1 2.5 0.00570 5.70 108 52.8 9 MET 1 1.250.00285 2.85 109 26.2 10 MET 1 0.63 0.00144 1.44 106 13.6 11 MET 1 0.320.00073 0.73 104 7.0 12 MET 1 2.5 0.00570 5.70 105 54.3 13 MET 1 1.250.00285 2.85 110 25.9 Notes on Table I: mg A-S - milligrams of sulfatedalumina activator-support μmol Zr/g - micromoles Zr per gram sulfatedalumina. Example 7 - the polymerization was conducted in the presence ofabout 26 milligrams of hydrogen added to the reactor initially, asdetermined by PV = nRT.

Generally, the results in Table II indicate a similar effect of variedZr loadings on the Mw and polydispersity of copolymers produced usingDMET 1 and MET 1. That is, the dinuclear metallocene compound, DMET 1,produced copolymers with properties similar to that produced using theMET 1 metallocene compound, across a broad range of Zr loadings. Bothcatalysts produced higher Mw polymers as the Zr loading was decreased.

FIG. 4 provides rheology curves for the polymers of Examples 3-7produced using a catalyst system including the dinuclear metallocene,DMET 1, or in the case of Example 8, the MET 1 metallocene.

TABLE II Comparison of DMET 1 and MET 1 at varied Zr loadings. μmolExample Catalyst Zr/g Mw/1000 PDI 3 DMET 1 55.6 227.7 2.76 4 DMET 1 28.0229.1 2.62 5 DMET 1 14.1 259.9 3.02 6 DMET 1 7.5 286.8 3.24 7 DMET 127.3 32.9 6.15 8 MET 1 52.8 221.6 2.71 9 MET 1 26.2 233.4 2.60 10 MET 113.6 275.6 2.68 11 MET 1 7.0 352.0 2.61 12 MET 1 54.3 223.3 2.59 13 MET1 25.9 242.7 2.27 Notes on Table II: μmol Zr/g - micromoles Zr per gramsulfated alumina. Mw - weight-average molecular weight. Mn -number-average molecular weight. PDI - polydispersity index, Mw/Mn.

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